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git/git-gui/lib/class.tcl

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git-gui: Define a simple class/method system As most of the git-gui interface is based upon "meta-widgets" that need to carry around a good deal of state (e.g. console windows, browser windows, blame viewer) we have a good deal of messy code that tries to store this meta-widget state in global arrays, where keys into the array are formed from a union of a unique "object instance id" and the field name. This is a simple class system for Tcl that allows us to hide much of that mess by making Tcl do what it does best; process strings to manipulate its own code during startup. Each object instance is placed into its own namespace. The namespace is created when the object instance is created and the namespace is destroyed when the object instance is removed from the system. Within that namespace we place variables for each field within the class; these variables can themselves be scalar values or full-blown Tcl arrays. A simple class might be defined as: class map { field data field size 0 constructor {} { return $this } method set {name value} { set data($name) $value incr size } method size {} { return $size } ifdeleted { return 0 } } All fields must be declared before any constructors or methods. This allows our class to generate a list of the fields so it can properly alter the definition of the constructor and method bodies prior to passing them off to Tcl for definition with proc. A field may optionally be given a default/initial value. This can only be done for non-array type fields. Constructors are given full access to all fields of the class, so they can initialize the data values. The default values of fields (if any) are set before the constructor runs, and the implicit local variable $this is initialized to the instance identifier. Methods are given access to fields they actually use in their body. Every method has an implicit "this" argument inserted as its first parameter; callers of methods must be sure they supply this value. Some basic optimization tricks are performed (but not much). We try to only upvar (locally bind) fields that are accessed within a method, but we err on the side of caution and may upvar more than we need to. If a variable is accessed only once within a method and that access is by $foo (read) we avoid the upvar and instead use [set foo] to obtain the value. This is slightly faster as Tcl does not need to lookup the variable twice. We also offer some small syntatic sugar for interacting with Tk and the fileevent callback system in Tcl. If a field (say "foo") is used as "@foo" we insert instead the true global variable name of that variable into the body of the constructor or method. This allows easy binding to Tk textvariable options, e.g.: label $w.title -textvariable @title Proper namespace callbacks can also be setup with the special cb proc that is defined in each namespace. [cb _foo a] will invoke the method _foo in the current namespace, passing it $this as the first (implied) parameter and a as the second parameter. This makes it very simple to connect an object instance to a -command option for a Tk widget or to a fileevent readable or writable for a file channel. Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2007-05-09 01:54:05 +02:00
# git-gui simple class/object fake-alike
# Copyright (C) 2007 Shawn Pearce
proc class {class body} {
if {[namespace exists $class]} {
error "class $class already declared"
}
git-gui: Teach class system to support [$this cmd] syntax Its handy to be able to ask an object to do something for you by handing it a subcommand. For example if we want to get the value of an object's private field the object could expose a method that would return that value. Application level code can then invoke "$inst get" to perform the method call. Tk uses this pattern for all of its widgets, so we'd certainly like to use it for our own mega-widgets that we might develop. Up until now we haven't needed such functionality, but I'm working on a new revision picker mega-widget that would benefit from it. To make this work we have to change the definition of $this to actually be a procedure within the namespace. By making $this a procedure any caller that has $this can call subcommands by passing them as the first argument to $this. That subcommand then needs to call the proper subroutine. Placing the dispatch procedure into the object's variable namespace ensures that it will always be deleted when the object is deleted. Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2007-06-30 10:34:59 +02:00
namespace eval $class "
git-gui: Define a simple class/method system As most of the git-gui interface is based upon "meta-widgets" that need to carry around a good deal of state (e.g. console windows, browser windows, blame viewer) we have a good deal of messy code that tries to store this meta-widget state in global arrays, where keys into the array are formed from a union of a unique "object instance id" and the field name. This is a simple class system for Tcl that allows us to hide much of that mess by making Tcl do what it does best; process strings to manipulate its own code during startup. Each object instance is placed into its own namespace. The namespace is created when the object instance is created and the namespace is destroyed when the object instance is removed from the system. Within that namespace we place variables for each field within the class; these variables can themselves be scalar values or full-blown Tcl arrays. A simple class might be defined as: class map { field data field size 0 constructor {} { return $this } method set {name value} { set data($name) $value incr size } method size {} { return $size } ifdeleted { return 0 } } All fields must be declared before any constructors or methods. This allows our class to generate a list of the fields so it can properly alter the definition of the constructor and method bodies prior to passing them off to Tcl for definition with proc. A field may optionally be given a default/initial value. This can only be done for non-array type fields. Constructors are given full access to all fields of the class, so they can initialize the data values. The default values of fields (if any) are set before the constructor runs, and the implicit local variable $this is initialized to the instance identifier. Methods are given access to fields they actually use in their body. Every method has an implicit "this" argument inserted as its first parameter; callers of methods must be sure they supply this value. Some basic optimization tricks are performed (but not much). We try to only upvar (locally bind) fields that are accessed within a method, but we err on the side of caution and may upvar more than we need to. If a variable is accessed only once within a method and that access is by $foo (read) we avoid the upvar and instead use [set foo] to obtain the value. This is slightly faster as Tcl does not need to lookup the variable twice. We also offer some small syntatic sugar for interacting with Tk and the fileevent callback system in Tcl. If a field (say "foo") is used as "@foo" we insert instead the true global variable name of that variable into the body of the constructor or method. This allows easy binding to Tk textvariable options, e.g.: label $w.title -textvariable @title Proper namespace callbacks can also be setup with the special cb proc that is defined in each namespace. [cb _foo a] will invoke the method _foo in the current namespace, passing it $this as the first (implied) parameter and a as the second parameter. This makes it very simple to connect an object instance to a -command option for a Tk widget or to a fileevent readable or writable for a file channel. Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2007-05-09 01:54:05 +02:00
variable __nextid 0
variable __sealed 0
variable __field_list {}
variable __field_array
proc cb {name args} {
upvar this this
git-gui: Teach class system to support [$this cmd] syntax Its handy to be able to ask an object to do something for you by handing it a subcommand. For example if we want to get the value of an object's private field the object could expose a method that would return that value. Application level code can then invoke "$inst get" to perform the method call. Tk uses this pattern for all of its widgets, so we'd certainly like to use it for our own mega-widgets that we might develop. Up until now we haven't needed such functionality, but I'm working on a new revision picker mega-widget that would benefit from it. To make this work we have to change the definition of $this to actually be a procedure within the namespace. By making $this a procedure any caller that has $this can call subcommands by passing them as the first argument to $this. That subcommand then needs to call the proper subroutine. Placing the dispatch procedure into the object's variable namespace ensures that it will always be deleted when the object is deleted. Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2007-06-30 10:34:59 +02:00
concat \[list ${class}::\$name \$this\] \$args
git-gui: Define a simple class/method system As most of the git-gui interface is based upon "meta-widgets" that need to carry around a good deal of state (e.g. console windows, browser windows, blame viewer) we have a good deal of messy code that tries to store this meta-widget state in global arrays, where keys into the array are formed from a union of a unique "object instance id" and the field name. This is a simple class system for Tcl that allows us to hide much of that mess by making Tcl do what it does best; process strings to manipulate its own code during startup. Each object instance is placed into its own namespace. The namespace is created when the object instance is created and the namespace is destroyed when the object instance is removed from the system. Within that namespace we place variables for each field within the class; these variables can themselves be scalar values or full-blown Tcl arrays. A simple class might be defined as: class map { field data field size 0 constructor {} { return $this } method set {name value} { set data($name) $value incr size } method size {} { return $size } ifdeleted { return 0 } } All fields must be declared before any constructors or methods. This allows our class to generate a list of the fields so it can properly alter the definition of the constructor and method bodies prior to passing them off to Tcl for definition with proc. A field may optionally be given a default/initial value. This can only be done for non-array type fields. Constructors are given full access to all fields of the class, so they can initialize the data values. The default values of fields (if any) are set before the constructor runs, and the implicit local variable $this is initialized to the instance identifier. Methods are given access to fields they actually use in their body. Every method has an implicit "this" argument inserted as its first parameter; callers of methods must be sure they supply this value. Some basic optimization tricks are performed (but not much). We try to only upvar (locally bind) fields that are accessed within a method, but we err on the side of caution and may upvar more than we need to. If a variable is accessed only once within a method and that access is by $foo (read) we avoid the upvar and instead use [set foo] to obtain the value. This is slightly faster as Tcl does not need to lookup the variable twice. We also offer some small syntatic sugar for interacting with Tk and the fileevent callback system in Tcl. If a field (say "foo") is used as "@foo" we insert instead the true global variable name of that variable into the body of the constructor or method. This allows easy binding to Tk textvariable options, e.g.: label $w.title -textvariable @title Proper namespace callbacks can also be setup with the special cb proc that is defined in each namespace. [cb _foo a] will invoke the method _foo in the current namespace, passing it $this as the first (implied) parameter and a as the second parameter. This makes it very simple to connect an object instance to a -command option for a Tk widget or to a fileevent readable or writable for a file channel. Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2007-05-09 01:54:05 +02:00
}
git-gui: Teach class system to support [$this cmd] syntax Its handy to be able to ask an object to do something for you by handing it a subcommand. For example if we want to get the value of an object's private field the object could expose a method that would return that value. Application level code can then invoke "$inst get" to perform the method call. Tk uses this pattern for all of its widgets, so we'd certainly like to use it for our own mega-widgets that we might develop. Up until now we haven't needed such functionality, but I'm working on a new revision picker mega-widget that would benefit from it. To make this work we have to change the definition of $this to actually be a procedure within the namespace. By making $this a procedure any caller that has $this can call subcommands by passing them as the first argument to $this. That subcommand then needs to call the proper subroutine. Placing the dispatch procedure into the object's variable namespace ensures that it will always be deleted when the object is deleted. Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2007-06-30 10:34:59 +02:00
"
git-gui: Define a simple class/method system As most of the git-gui interface is based upon "meta-widgets" that need to carry around a good deal of state (e.g. console windows, browser windows, blame viewer) we have a good deal of messy code that tries to store this meta-widget state in global arrays, where keys into the array are formed from a union of a unique "object instance id" and the field name. This is a simple class system for Tcl that allows us to hide much of that mess by making Tcl do what it does best; process strings to manipulate its own code during startup. Each object instance is placed into its own namespace. The namespace is created when the object instance is created and the namespace is destroyed when the object instance is removed from the system. Within that namespace we place variables for each field within the class; these variables can themselves be scalar values or full-blown Tcl arrays. A simple class might be defined as: class map { field data field size 0 constructor {} { return $this } method set {name value} { set data($name) $value incr size } method size {} { return $size } ifdeleted { return 0 } } All fields must be declared before any constructors or methods. This allows our class to generate a list of the fields so it can properly alter the definition of the constructor and method bodies prior to passing them off to Tcl for definition with proc. A field may optionally be given a default/initial value. This can only be done for non-array type fields. Constructors are given full access to all fields of the class, so they can initialize the data values. The default values of fields (if any) are set before the constructor runs, and the implicit local variable $this is initialized to the instance identifier. Methods are given access to fields they actually use in their body. Every method has an implicit "this" argument inserted as its first parameter; callers of methods must be sure they supply this value. Some basic optimization tricks are performed (but not much). We try to only upvar (locally bind) fields that are accessed within a method, but we err on the side of caution and may upvar more than we need to. If a variable is accessed only once within a method and that access is by $foo (read) we avoid the upvar and instead use [set foo] to obtain the value. This is slightly faster as Tcl does not need to lookup the variable twice. We also offer some small syntatic sugar for interacting with Tk and the fileevent callback system in Tcl. If a field (say "foo") is used as "@foo" we insert instead the true global variable name of that variable into the body of the constructor or method. This allows easy binding to Tk textvariable options, e.g.: label $w.title -textvariable @title Proper namespace callbacks can also be setup with the special cb proc that is defined in each namespace. [cb _foo a] will invoke the method _foo in the current namespace, passing it $this as the first (implied) parameter and a as the second parameter. This makes it very simple to connect an object instance to a -command option for a Tk widget or to a fileevent readable or writable for a file channel. Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2007-05-09 01:54:05 +02:00
namespace eval $class $body
}
proc field {name args} {
set class [uplevel {namespace current}]
variable ${class}::__sealed
variable ${class}::__field_array
switch [llength $args] {
0 { set new [list $name] }
1 { set new [list $name [lindex $args 0]] }
default { error "wrong # args: field name value?" }
}
if {$__sealed} {
error "class $class is sealed (cannot add new fields)"
}
if {[catch {set old $__field_array($name)}]} {
variable ${class}::__field_list
lappend __field_list $new
set __field_array($name) 1
} else {
error "field $name already declared"
}
}
proc constructor {name params body} {
set class [uplevel {namespace current}]
set ${class}::__sealed 1
variable ${class}::__field_list
set mbodyc {}
append mbodyc {set this } $class
git-gui: Teach class system to support [$this cmd] syntax Its handy to be able to ask an object to do something for you by handing it a subcommand. For example if we want to get the value of an object's private field the object could expose a method that would return that value. Application level code can then invoke "$inst get" to perform the method call. Tk uses this pattern for all of its widgets, so we'd certainly like to use it for our own mega-widgets that we might develop. Up until now we haven't needed such functionality, but I'm working on a new revision picker mega-widget that would benefit from it. To make this work we have to change the definition of $this to actually be a procedure within the namespace. By making $this a procedure any caller that has $this can call subcommands by passing them as the first argument to $this. That subcommand then needs to call the proper subroutine. Placing the dispatch procedure into the object's variable namespace ensures that it will always be deleted when the object is deleted. Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2007-06-30 10:34:59 +02:00
append mbodyc {::__o[incr } $class {::__nextid]::__d} \;
append mbodyc {create_this } $class \;
append mbodyc {set __this [namespace qualifiers $this]} \;
git-gui: Define a simple class/method system As most of the git-gui interface is based upon "meta-widgets" that need to carry around a good deal of state (e.g. console windows, browser windows, blame viewer) we have a good deal of messy code that tries to store this meta-widget state in global arrays, where keys into the array are formed from a union of a unique "object instance id" and the field name. This is a simple class system for Tcl that allows us to hide much of that mess by making Tcl do what it does best; process strings to manipulate its own code during startup. Each object instance is placed into its own namespace. The namespace is created when the object instance is created and the namespace is destroyed when the object instance is removed from the system. Within that namespace we place variables for each field within the class; these variables can themselves be scalar values or full-blown Tcl arrays. A simple class might be defined as: class map { field data field size 0 constructor {} { return $this } method set {name value} { set data($name) $value incr size } method size {} { return $size } ifdeleted { return 0 } } All fields must be declared before any constructors or methods. This allows our class to generate a list of the fields so it can properly alter the definition of the constructor and method bodies prior to passing them off to Tcl for definition with proc. A field may optionally be given a default/initial value. This can only be done for non-array type fields. Constructors are given full access to all fields of the class, so they can initialize the data values. The default values of fields (if any) are set before the constructor runs, and the implicit local variable $this is initialized to the instance identifier. Methods are given access to fields they actually use in their body. Every method has an implicit "this" argument inserted as its first parameter; callers of methods must be sure they supply this value. Some basic optimization tricks are performed (but not much). We try to only upvar (locally bind) fields that are accessed within a method, but we err on the side of caution and may upvar more than we need to. If a variable is accessed only once within a method and that access is by $foo (read) we avoid the upvar and instead use [set foo] to obtain the value. This is slightly faster as Tcl does not need to lookup the variable twice. We also offer some small syntatic sugar for interacting with Tk and the fileevent callback system in Tcl. If a field (say "foo") is used as "@foo" we insert instead the true global variable name of that variable into the body of the constructor or method. This allows easy binding to Tk textvariable options, e.g.: label $w.title -textvariable @title Proper namespace callbacks can also be setup with the special cb proc that is defined in each namespace. [cb _foo a] will invoke the method _foo in the current namespace, passing it $this as the first (implied) parameter and a as the second parameter. This makes it very simple to connect an object instance to a -command option for a Tk widget or to a fileevent readable or writable for a file channel. Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2007-05-09 01:54:05 +02:00
if {$__field_list ne {}} {
append mbodyc {upvar #0}
foreach n $__field_list {
set n [lindex $n 0]
git-gui: Teach class system to support [$this cmd] syntax Its handy to be able to ask an object to do something for you by handing it a subcommand. For example if we want to get the value of an object's private field the object could expose a method that would return that value. Application level code can then invoke "$inst get" to perform the method call. Tk uses this pattern for all of its widgets, so we'd certainly like to use it for our own mega-widgets that we might develop. Up until now we haven't needed such functionality, but I'm working on a new revision picker mega-widget that would benefit from it. To make this work we have to change the definition of $this to actually be a procedure within the namespace. By making $this a procedure any caller that has $this can call subcommands by passing them as the first argument to $this. That subcommand then needs to call the proper subroutine. Placing the dispatch procedure into the object's variable namespace ensures that it will always be deleted when the object is deleted. Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2007-06-30 10:34:59 +02:00
append mbodyc { ${__this}::} $n { } $n
regsub -all @$n\\M $body "\${__this}::$n" body
git-gui: Define a simple class/method system As most of the git-gui interface is based upon "meta-widgets" that need to carry around a good deal of state (e.g. console windows, browser windows, blame viewer) we have a good deal of messy code that tries to store this meta-widget state in global arrays, where keys into the array are formed from a union of a unique "object instance id" and the field name. This is a simple class system for Tcl that allows us to hide much of that mess by making Tcl do what it does best; process strings to manipulate its own code during startup. Each object instance is placed into its own namespace. The namespace is created when the object instance is created and the namespace is destroyed when the object instance is removed from the system. Within that namespace we place variables for each field within the class; these variables can themselves be scalar values or full-blown Tcl arrays. A simple class might be defined as: class map { field data field size 0 constructor {} { return $this } method set {name value} { set data($name) $value incr size } method size {} { return $size } ifdeleted { return 0 } } All fields must be declared before any constructors or methods. This allows our class to generate a list of the fields so it can properly alter the definition of the constructor and method bodies prior to passing them off to Tcl for definition with proc. A field may optionally be given a default/initial value. This can only be done for non-array type fields. Constructors are given full access to all fields of the class, so they can initialize the data values. The default values of fields (if any) are set before the constructor runs, and the implicit local variable $this is initialized to the instance identifier. Methods are given access to fields they actually use in their body. Every method has an implicit "this" argument inserted as its first parameter; callers of methods must be sure they supply this value. Some basic optimization tricks are performed (but not much). We try to only upvar (locally bind) fields that are accessed within a method, but we err on the side of caution and may upvar more than we need to. If a variable is accessed only once within a method and that access is by $foo (read) we avoid the upvar and instead use [set foo] to obtain the value. This is slightly faster as Tcl does not need to lookup the variable twice. We also offer some small syntatic sugar for interacting with Tk and the fileevent callback system in Tcl. If a field (say "foo") is used as "@foo" we insert instead the true global variable name of that variable into the body of the constructor or method. This allows easy binding to Tk textvariable options, e.g.: label $w.title -textvariable @title Proper namespace callbacks can also be setup with the special cb proc that is defined in each namespace. [cb _foo a] will invoke the method _foo in the current namespace, passing it $this as the first (implied) parameter and a as the second parameter. This makes it very simple to connect an object instance to a -command option for a Tk widget or to a fileevent readable or writable for a file channel. Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2007-05-09 01:54:05 +02:00
}
append mbodyc \;
foreach n $__field_list {
if {[llength $n] == 2} {
append mbodyc \
{set } [lindex $n 0] { } [list [lindex $n 1]] \;
}
}
}
append mbodyc $body
namespace eval $class [list proc $name $params $mbodyc]
}
proc method {name params body {deleted {}} {del_body {}}} {
set class [uplevel {namespace current}]
set ${class}::__sealed 1
variable ${class}::__field_list
set params [linsert $params 0 this]
set mbodyc {}
git-gui: Teach class system to support [$this cmd] syntax Its handy to be able to ask an object to do something for you by handing it a subcommand. For example if we want to get the value of an object's private field the object could expose a method that would return that value. Application level code can then invoke "$inst get" to perform the method call. Tk uses this pattern for all of its widgets, so we'd certainly like to use it for our own mega-widgets that we might develop. Up until now we haven't needed such functionality, but I'm working on a new revision picker mega-widget that would benefit from it. To make this work we have to change the definition of $this to actually be a procedure within the namespace. By making $this a procedure any caller that has $this can call subcommands by passing them as the first argument to $this. That subcommand then needs to call the proper subroutine. Placing the dispatch procedure into the object's variable namespace ensures that it will always be deleted when the object is deleted. Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2007-06-30 10:34:59 +02:00
append mbodyc {set __this [namespace qualifiers $this]} \;
git-gui: Define a simple class/method system As most of the git-gui interface is based upon "meta-widgets" that need to carry around a good deal of state (e.g. console windows, browser windows, blame viewer) we have a good deal of messy code that tries to store this meta-widget state in global arrays, where keys into the array are formed from a union of a unique "object instance id" and the field name. This is a simple class system for Tcl that allows us to hide much of that mess by making Tcl do what it does best; process strings to manipulate its own code during startup. Each object instance is placed into its own namespace. The namespace is created when the object instance is created and the namespace is destroyed when the object instance is removed from the system. Within that namespace we place variables for each field within the class; these variables can themselves be scalar values or full-blown Tcl arrays. A simple class might be defined as: class map { field data field size 0 constructor {} { return $this } method set {name value} { set data($name) $value incr size } method size {} { return $size } ifdeleted { return 0 } } All fields must be declared before any constructors or methods. This allows our class to generate a list of the fields so it can properly alter the definition of the constructor and method bodies prior to passing them off to Tcl for definition with proc. A field may optionally be given a default/initial value. This can only be done for non-array type fields. Constructors are given full access to all fields of the class, so they can initialize the data values. The default values of fields (if any) are set before the constructor runs, and the implicit local variable $this is initialized to the instance identifier. Methods are given access to fields they actually use in their body. Every method has an implicit "this" argument inserted as its first parameter; callers of methods must be sure they supply this value. Some basic optimization tricks are performed (but not much). We try to only upvar (locally bind) fields that are accessed within a method, but we err on the side of caution and may upvar more than we need to. If a variable is accessed only once within a method and that access is by $foo (read) we avoid the upvar and instead use [set foo] to obtain the value. This is slightly faster as Tcl does not need to lookup the variable twice. We also offer some small syntatic sugar for interacting with Tk and the fileevent callback system in Tcl. If a field (say "foo") is used as "@foo" we insert instead the true global variable name of that variable into the body of the constructor or method. This allows easy binding to Tk textvariable options, e.g.: label $w.title -textvariable @title Proper namespace callbacks can also be setup with the special cb proc that is defined in each namespace. [cb _foo a] will invoke the method _foo in the current namespace, passing it $this as the first (implied) parameter and a as the second parameter. This makes it very simple to connect an object instance to a -command option for a Tk widget or to a fileevent readable or writable for a file channel. Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2007-05-09 01:54:05 +02:00
switch $deleted {
{} {}
ifdeleted {
git-gui: Teach class system to support [$this cmd] syntax Its handy to be able to ask an object to do something for you by handing it a subcommand. For example if we want to get the value of an object's private field the object could expose a method that would return that value. Application level code can then invoke "$inst get" to perform the method call. Tk uses this pattern for all of its widgets, so we'd certainly like to use it for our own mega-widgets that we might develop. Up until now we haven't needed such functionality, but I'm working on a new revision picker mega-widget that would benefit from it. To make this work we have to change the definition of $this to actually be a procedure within the namespace. By making $this a procedure any caller that has $this can call subcommands by passing them as the first argument to $this. That subcommand then needs to call the proper subroutine. Placing the dispatch procedure into the object's variable namespace ensures that it will always be deleted when the object is deleted. Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2007-06-30 10:34:59 +02:00
append mbodyc {if {![namespace exists $__this]} }
git-gui: Define a simple class/method system As most of the git-gui interface is based upon "meta-widgets" that need to carry around a good deal of state (e.g. console windows, browser windows, blame viewer) we have a good deal of messy code that tries to store this meta-widget state in global arrays, where keys into the array are formed from a union of a unique "object instance id" and the field name. This is a simple class system for Tcl that allows us to hide much of that mess by making Tcl do what it does best; process strings to manipulate its own code during startup. Each object instance is placed into its own namespace. The namespace is created when the object instance is created and the namespace is destroyed when the object instance is removed from the system. Within that namespace we place variables for each field within the class; these variables can themselves be scalar values or full-blown Tcl arrays. A simple class might be defined as: class map { field data field size 0 constructor {} { return $this } method set {name value} { set data($name) $value incr size } method size {} { return $size } ifdeleted { return 0 } } All fields must be declared before any constructors or methods. This allows our class to generate a list of the fields so it can properly alter the definition of the constructor and method bodies prior to passing them off to Tcl for definition with proc. A field may optionally be given a default/initial value. This can only be done for non-array type fields. Constructors are given full access to all fields of the class, so they can initialize the data values. The default values of fields (if any) are set before the constructor runs, and the implicit local variable $this is initialized to the instance identifier. Methods are given access to fields they actually use in their body. Every method has an implicit "this" argument inserted as its first parameter; callers of methods must be sure they supply this value. Some basic optimization tricks are performed (but not much). We try to only upvar (locally bind) fields that are accessed within a method, but we err on the side of caution and may upvar more than we need to. If a variable is accessed only once within a method and that access is by $foo (read) we avoid the upvar and instead use [set foo] to obtain the value. This is slightly faster as Tcl does not need to lookup the variable twice. We also offer some small syntatic sugar for interacting with Tk and the fileevent callback system in Tcl. If a field (say "foo") is used as "@foo" we insert instead the true global variable name of that variable into the body of the constructor or method. This allows easy binding to Tk textvariable options, e.g.: label $w.title -textvariable @title Proper namespace callbacks can also be setup with the special cb proc that is defined in each namespace. [cb _foo a] will invoke the method _foo in the current namespace, passing it $this as the first (implied) parameter and a as the second parameter. This makes it very simple to connect an object instance to a -command option for a Tk widget or to a fileevent readable or writable for a file channel. Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2007-05-09 01:54:05 +02:00
append mbodyc \{ $del_body \; return \} \;
}
default {
error "wrong # args: method name args body (ifdeleted body)?"
}
}
set decl {}
foreach n $__field_list {
set n [lindex $n 0]
if {[regexp -- $n\\M $body]} {
if { [regexp -all -- $n\\M $body] == 1
git-gui: Don't attempt to inline array reads in methods If a variable reference to a field is to an array, and it is the only reference to that field in that method we cannot make it an inlined [set foo] call as the regexp was converting the Tcl code wrong. We were producing "[set foo](x)" for "$foo(x)", and that isn't valid Tcl when foo is an array. So we just punt if the only occurance has a ( after it. Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2007-05-09 03:31:31 +02:00
&& [regexp -all -- \\\$$n\\M $body] == 1
&& [regexp -all -- \\\$$n\\( $body] == 0} {
git-gui: Teach class system to support [$this cmd] syntax Its handy to be able to ask an object to do something for you by handing it a subcommand. For example if we want to get the value of an object's private field the object could expose a method that would return that value. Application level code can then invoke "$inst get" to perform the method call. Tk uses this pattern for all of its widgets, so we'd certainly like to use it for our own mega-widgets that we might develop. Up until now we haven't needed such functionality, but I'm working on a new revision picker mega-widget that would benefit from it. To make this work we have to change the definition of $this to actually be a procedure within the namespace. By making $this a procedure any caller that has $this can call subcommands by passing them as the first argument to $this. That subcommand then needs to call the proper subroutine. Placing the dispatch procedure into the object's variable namespace ensures that it will always be deleted when the object is deleted. Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2007-06-30 10:34:59 +02:00
regsub -all \
\\\$$n\\M $body \
"\[set \${__this}::$n\]" body
git-gui: Define a simple class/method system As most of the git-gui interface is based upon "meta-widgets" that need to carry around a good deal of state (e.g. console windows, browser windows, blame viewer) we have a good deal of messy code that tries to store this meta-widget state in global arrays, where keys into the array are formed from a union of a unique "object instance id" and the field name. This is a simple class system for Tcl that allows us to hide much of that mess by making Tcl do what it does best; process strings to manipulate its own code during startup. Each object instance is placed into its own namespace. The namespace is created when the object instance is created and the namespace is destroyed when the object instance is removed from the system. Within that namespace we place variables for each field within the class; these variables can themselves be scalar values or full-blown Tcl arrays. A simple class might be defined as: class map { field data field size 0 constructor {} { return $this } method set {name value} { set data($name) $value incr size } method size {} { return $size } ifdeleted { return 0 } } All fields must be declared before any constructors or methods. This allows our class to generate a list of the fields so it can properly alter the definition of the constructor and method bodies prior to passing them off to Tcl for definition with proc. A field may optionally be given a default/initial value. This can only be done for non-array type fields. Constructors are given full access to all fields of the class, so they can initialize the data values. The default values of fields (if any) are set before the constructor runs, and the implicit local variable $this is initialized to the instance identifier. Methods are given access to fields they actually use in their body. Every method has an implicit "this" argument inserted as its first parameter; callers of methods must be sure they supply this value. Some basic optimization tricks are performed (but not much). We try to only upvar (locally bind) fields that are accessed within a method, but we err on the side of caution and may upvar more than we need to. If a variable is accessed only once within a method and that access is by $foo (read) we avoid the upvar and instead use [set foo] to obtain the value. This is slightly faster as Tcl does not need to lookup the variable twice. We also offer some small syntatic sugar for interacting with Tk and the fileevent callback system in Tcl. If a field (say "foo") is used as "@foo" we insert instead the true global variable name of that variable into the body of the constructor or method. This allows easy binding to Tk textvariable options, e.g.: label $w.title -textvariable @title Proper namespace callbacks can also be setup with the special cb proc that is defined in each namespace. [cb _foo a] will invoke the method _foo in the current namespace, passing it $this as the first (implied) parameter and a as the second parameter. This makes it very simple to connect an object instance to a -command option for a Tk widget or to a fileevent readable or writable for a file channel. Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2007-05-09 01:54:05 +02:00
} else {
git-gui: Teach class system to support [$this cmd] syntax Its handy to be able to ask an object to do something for you by handing it a subcommand. For example if we want to get the value of an object's private field the object could expose a method that would return that value. Application level code can then invoke "$inst get" to perform the method call. Tk uses this pattern for all of its widgets, so we'd certainly like to use it for our own mega-widgets that we might develop. Up until now we haven't needed such functionality, but I'm working on a new revision picker mega-widget that would benefit from it. To make this work we have to change the definition of $this to actually be a procedure within the namespace. By making $this a procedure any caller that has $this can call subcommands by passing them as the first argument to $this. That subcommand then needs to call the proper subroutine. Placing the dispatch procedure into the object's variable namespace ensures that it will always be deleted when the object is deleted. Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2007-06-30 10:34:59 +02:00
append decl { ${__this}::} $n { } $n
regsub -all @$n\\M $body "\${__this}::$n" body
git-gui: Define a simple class/method system As most of the git-gui interface is based upon "meta-widgets" that need to carry around a good deal of state (e.g. console windows, browser windows, blame viewer) we have a good deal of messy code that tries to store this meta-widget state in global arrays, where keys into the array are formed from a union of a unique "object instance id" and the field name. This is a simple class system for Tcl that allows us to hide much of that mess by making Tcl do what it does best; process strings to manipulate its own code during startup. Each object instance is placed into its own namespace. The namespace is created when the object instance is created and the namespace is destroyed when the object instance is removed from the system. Within that namespace we place variables for each field within the class; these variables can themselves be scalar values or full-blown Tcl arrays. A simple class might be defined as: class map { field data field size 0 constructor {} { return $this } method set {name value} { set data($name) $value incr size } method size {} { return $size } ifdeleted { return 0 } } All fields must be declared before any constructors or methods. This allows our class to generate a list of the fields so it can properly alter the definition of the constructor and method bodies prior to passing them off to Tcl for definition with proc. A field may optionally be given a default/initial value. This can only be done for non-array type fields. Constructors are given full access to all fields of the class, so they can initialize the data values. The default values of fields (if any) are set before the constructor runs, and the implicit local variable $this is initialized to the instance identifier. Methods are given access to fields they actually use in their body. Every method has an implicit "this" argument inserted as its first parameter; callers of methods must be sure they supply this value. Some basic optimization tricks are performed (but not much). We try to only upvar (locally bind) fields that are accessed within a method, but we err on the side of caution and may upvar more than we need to. If a variable is accessed only once within a method and that access is by $foo (read) we avoid the upvar and instead use [set foo] to obtain the value. This is slightly faster as Tcl does not need to lookup the variable twice. We also offer some small syntatic sugar for interacting with Tk and the fileevent callback system in Tcl. If a field (say "foo") is used as "@foo" we insert instead the true global variable name of that variable into the body of the constructor or method. This allows easy binding to Tk textvariable options, e.g.: label $w.title -textvariable @title Proper namespace callbacks can also be setup with the special cb proc that is defined in each namespace. [cb _foo a] will invoke the method _foo in the current namespace, passing it $this as the first (implied) parameter and a as the second parameter. This makes it very simple to connect an object instance to a -command option for a Tk widget or to a fileevent readable or writable for a file channel. Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2007-05-09 01:54:05 +02:00
}
}
}
if {$decl ne {}} {
append mbodyc {upvar #0} $decl \;
}
append mbodyc $body
namespace eval $class [list proc $name $params $mbodyc]
}
git-gui: Teach class system to support [$this cmd] syntax Its handy to be able to ask an object to do something for you by handing it a subcommand. For example if we want to get the value of an object's private field the object could expose a method that would return that value. Application level code can then invoke "$inst get" to perform the method call. Tk uses this pattern for all of its widgets, so we'd certainly like to use it for our own mega-widgets that we might develop. Up until now we haven't needed such functionality, but I'm working on a new revision picker mega-widget that would benefit from it. To make this work we have to change the definition of $this to actually be a procedure within the namespace. By making $this a procedure any caller that has $this can call subcommands by passing them as the first argument to $this. That subcommand then needs to call the proper subroutine. Placing the dispatch procedure into the object's variable namespace ensures that it will always be deleted when the object is deleted. Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2007-06-30 10:34:59 +02:00
proc create_this {class} {
upvar this this
namespace eval [namespace qualifiers $this] [list proc \
[namespace tail $this] \
[list name args] \
"eval \[list ${class}::\$name $this\] \$args" \
]
}
git-gui: Define a simple class/method system As most of the git-gui interface is based upon "meta-widgets" that need to carry around a good deal of state (e.g. console windows, browser windows, blame viewer) we have a good deal of messy code that tries to store this meta-widget state in global arrays, where keys into the array are formed from a union of a unique "object instance id" and the field name. This is a simple class system for Tcl that allows us to hide much of that mess by making Tcl do what it does best; process strings to manipulate its own code during startup. Each object instance is placed into its own namespace. The namespace is created when the object instance is created and the namespace is destroyed when the object instance is removed from the system. Within that namespace we place variables for each field within the class; these variables can themselves be scalar values or full-blown Tcl arrays. A simple class might be defined as: class map { field data field size 0 constructor {} { return $this } method set {name value} { set data($name) $value incr size } method size {} { return $size } ifdeleted { return 0 } } All fields must be declared before any constructors or methods. This allows our class to generate a list of the fields so it can properly alter the definition of the constructor and method bodies prior to passing them off to Tcl for definition with proc. A field may optionally be given a default/initial value. This can only be done for non-array type fields. Constructors are given full access to all fields of the class, so they can initialize the data values. The default values of fields (if any) are set before the constructor runs, and the implicit local variable $this is initialized to the instance identifier. Methods are given access to fields they actually use in their body. Every method has an implicit "this" argument inserted as its first parameter; callers of methods must be sure they supply this value. Some basic optimization tricks are performed (but not much). We try to only upvar (locally bind) fields that are accessed within a method, but we err on the side of caution and may upvar more than we need to. If a variable is accessed only once within a method and that access is by $foo (read) we avoid the upvar and instead use [set foo] to obtain the value. This is slightly faster as Tcl does not need to lookup the variable twice. We also offer some small syntatic sugar for interacting with Tk and the fileevent callback system in Tcl. If a field (say "foo") is used as "@foo" we insert instead the true global variable name of that variable into the body of the constructor or method. This allows easy binding to Tk textvariable options, e.g.: label $w.title -textvariable @title Proper namespace callbacks can also be setup with the special cb proc that is defined in each namespace. [cb _foo a] will invoke the method _foo in the current namespace, passing it $this as the first (implied) parameter and a as the second parameter. This makes it very simple to connect an object instance to a -command option for a Tk widget or to a fileevent readable or writable for a file channel. Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2007-05-09 01:54:05 +02:00
proc delete_this {{t {}}} {
if {$t eq {}} {
upvar this this
set t $this
}
git-gui: Teach class system to support [$this cmd] syntax Its handy to be able to ask an object to do something for you by handing it a subcommand. For example if we want to get the value of an object's private field the object could expose a method that would return that value. Application level code can then invoke "$inst get" to perform the method call. Tk uses this pattern for all of its widgets, so we'd certainly like to use it for our own mega-widgets that we might develop. Up until now we haven't needed such functionality, but I'm working on a new revision picker mega-widget that would benefit from it. To make this work we have to change the definition of $this to actually be a procedure within the namespace. By making $this a procedure any caller that has $this can call subcommands by passing them as the first argument to $this. That subcommand then needs to call the proper subroutine. Placing the dispatch procedure into the object's variable namespace ensures that it will always be deleted when the object is deleted. Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2007-06-30 10:34:59 +02:00
set t [namespace qualifiers $t]
git-gui: Define a simple class/method system As most of the git-gui interface is based upon "meta-widgets" that need to carry around a good deal of state (e.g. console windows, browser windows, blame viewer) we have a good deal of messy code that tries to store this meta-widget state in global arrays, where keys into the array are formed from a union of a unique "object instance id" and the field name. This is a simple class system for Tcl that allows us to hide much of that mess by making Tcl do what it does best; process strings to manipulate its own code during startup. Each object instance is placed into its own namespace. The namespace is created when the object instance is created and the namespace is destroyed when the object instance is removed from the system. Within that namespace we place variables for each field within the class; these variables can themselves be scalar values or full-blown Tcl arrays. A simple class might be defined as: class map { field data field size 0 constructor {} { return $this } method set {name value} { set data($name) $value incr size } method size {} { return $size } ifdeleted { return 0 } } All fields must be declared before any constructors or methods. This allows our class to generate a list of the fields so it can properly alter the definition of the constructor and method bodies prior to passing them off to Tcl for definition with proc. A field may optionally be given a default/initial value. This can only be done for non-array type fields. Constructors are given full access to all fields of the class, so they can initialize the data values. The default values of fields (if any) are set before the constructor runs, and the implicit local variable $this is initialized to the instance identifier. Methods are given access to fields they actually use in their body. Every method has an implicit "this" argument inserted as its first parameter; callers of methods must be sure they supply this value. Some basic optimization tricks are performed (but not much). We try to only upvar (locally bind) fields that are accessed within a method, but we err on the side of caution and may upvar more than we need to. If a variable is accessed only once within a method and that access is by $foo (read) we avoid the upvar and instead use [set foo] to obtain the value. This is slightly faster as Tcl does not need to lookup the variable twice. We also offer some small syntatic sugar for interacting with Tk and the fileevent callback system in Tcl. If a field (say "foo") is used as "@foo" we insert instead the true global variable name of that variable into the body of the constructor or method. This allows easy binding to Tk textvariable options, e.g.: label $w.title -textvariable @title Proper namespace callbacks can also be setup with the special cb proc that is defined in each namespace. [cb _foo a] will invoke the method _foo in the current namespace, passing it $this as the first (implied) parameter and a as the second parameter. This makes it very simple to connect an object instance to a -command option for a Tk widget or to a fileevent readable or writable for a file channel. Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2007-05-09 01:54:05 +02:00
if {[namespace exists $t]} {namespace delete $t}
}
git-gui: Save geometry before the window layout is damaged Because Tk does not assure us the order that it will process children in before it destroys the main toplevel we cannot safely save our geometry data during a "bind . <Destroy>" event binding. The geometry may have already changed as a result of a one or more children being removed from the layout. This was pointed out in gitk by Mark Levedahl, and patched over there by commit b6047c5a8166a71e01c6b63ebbb67c6894d95114. So we now also use "wm protocol . WM_DELETE_WINDOW" to detect when the window is closed by the user, and forward that close event to our main do_quit routine. Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2007-06-12 05:52:43 +02:00
proc make_toplevel {t w args} {
upvar $t top $w pfx this this
if {[llength $args] % 2} {
error "make_toplevel topvar winvar {options}"
}
set autodelete 1
foreach {name value} $args {
switch -exact -- $name {
-autodelete {set autodelete $value}
default {error "unsupported option $name"}
}
}
git-gui: Fix window manager problems on ion3 cehteh on #git noticed that secondary windows such as console windows from push/fetch/merge or the blame browser failed on ion when we tried to open them a second time. The issue turned out to be the fact that on ion [winfo ismapped .] returns false if . is not visible right now because it has been obscured by another window in the same panel. So we need to keep track of whether or not the root window has been displayed for this application, and once it has been we cannot ever assume that ismapped is going to return true. Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2007-08-20 06:53:04 +02:00
if {$::root_exists || [winfo ismapped .]} {
git-gui: Define a simple class/method system As most of the git-gui interface is based upon "meta-widgets" that need to carry around a good deal of state (e.g. console windows, browser windows, blame viewer) we have a good deal of messy code that tries to store this meta-widget state in global arrays, where keys into the array are formed from a union of a unique "object instance id" and the field name. This is a simple class system for Tcl that allows us to hide much of that mess by making Tcl do what it does best; process strings to manipulate its own code during startup. Each object instance is placed into its own namespace. The namespace is created when the object instance is created and the namespace is destroyed when the object instance is removed from the system. Within that namespace we place variables for each field within the class; these variables can themselves be scalar values or full-blown Tcl arrays. A simple class might be defined as: class map { field data field size 0 constructor {} { return $this } method set {name value} { set data($name) $value incr size } method size {} { return $size } ifdeleted { return 0 } } All fields must be declared before any constructors or methods. This allows our class to generate a list of the fields so it can properly alter the definition of the constructor and method bodies prior to passing them off to Tcl for definition with proc. A field may optionally be given a default/initial value. This can only be done for non-array type fields. Constructors are given full access to all fields of the class, so they can initialize the data values. The default values of fields (if any) are set before the constructor runs, and the implicit local variable $this is initialized to the instance identifier. Methods are given access to fields they actually use in their body. Every method has an implicit "this" argument inserted as its first parameter; callers of methods must be sure they supply this value. Some basic optimization tricks are performed (but not much). We try to only upvar (locally bind) fields that are accessed within a method, but we err on the side of caution and may upvar more than we need to. If a variable is accessed only once within a method and that access is by $foo (read) we avoid the upvar and instead use [set foo] to obtain the value. This is slightly faster as Tcl does not need to lookup the variable twice. We also offer some small syntatic sugar for interacting with Tk and the fileevent callback system in Tcl. If a field (say "foo") is used as "@foo" we insert instead the true global variable name of that variable into the body of the constructor or method. This allows easy binding to Tk textvariable options, e.g.: label $w.title -textvariable @title Proper namespace callbacks can also be setup with the special cb proc that is defined in each namespace. [cb _foo a] will invoke the method _foo in the current namespace, passing it $this as the first (implied) parameter and a as the second parameter. This makes it very simple to connect an object instance to a -command option for a Tk widget or to a fileevent readable or writable for a file channel. Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2007-05-09 01:54:05 +02:00
regsub -all {::} $this {__} w
set top .$w
set pfx $top
toplevel $top
git-gui: Fix window manager problems on ion3 cehteh on #git noticed that secondary windows such as console windows from push/fetch/merge or the blame browser failed on ion when we tried to open them a second time. The issue turned out to be the fact that on ion [winfo ismapped .] returns false if . is not visible right now because it has been obscured by another window in the same panel. So we need to keep track of whether or not the root window has been displayed for this application, and once it has been we cannot ever assume that ismapped is going to return true. Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2007-08-20 06:53:04 +02:00
set ::root_exists 1
git-gui: Define a simple class/method system As most of the git-gui interface is based upon "meta-widgets" that need to carry around a good deal of state (e.g. console windows, browser windows, blame viewer) we have a good deal of messy code that tries to store this meta-widget state in global arrays, where keys into the array are formed from a union of a unique "object instance id" and the field name. This is a simple class system for Tcl that allows us to hide much of that mess by making Tcl do what it does best; process strings to manipulate its own code during startup. Each object instance is placed into its own namespace. The namespace is created when the object instance is created and the namespace is destroyed when the object instance is removed from the system. Within that namespace we place variables for each field within the class; these variables can themselves be scalar values or full-blown Tcl arrays. A simple class might be defined as: class map { field data field size 0 constructor {} { return $this } method set {name value} { set data($name) $value incr size } method size {} { return $size } ifdeleted { return 0 } } All fields must be declared before any constructors or methods. This allows our class to generate a list of the fields so it can properly alter the definition of the constructor and method bodies prior to passing them off to Tcl for definition with proc. A field may optionally be given a default/initial value. This can only be done for non-array type fields. Constructors are given full access to all fields of the class, so they can initialize the data values. The default values of fields (if any) are set before the constructor runs, and the implicit local variable $this is initialized to the instance identifier. Methods are given access to fields they actually use in their body. Every method has an implicit "this" argument inserted as its first parameter; callers of methods must be sure they supply this value. Some basic optimization tricks are performed (but not much). We try to only upvar (locally bind) fields that are accessed within a method, but we err on the side of caution and may upvar more than we need to. If a variable is accessed only once within a method and that access is by $foo (read) we avoid the upvar and instead use [set foo] to obtain the value. This is slightly faster as Tcl does not need to lookup the variable twice. We also offer some small syntatic sugar for interacting with Tk and the fileevent callback system in Tcl. If a field (say "foo") is used as "@foo" we insert instead the true global variable name of that variable into the body of the constructor or method. This allows easy binding to Tk textvariable options, e.g.: label $w.title -textvariable @title Proper namespace callbacks can also be setup with the special cb proc that is defined in each namespace. [cb _foo a] will invoke the method _foo in the current namespace, passing it $this as the first (implied) parameter and a as the second parameter. This makes it very simple to connect an object instance to a -command option for a Tk widget or to a fileevent readable or writable for a file channel. Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2007-05-09 01:54:05 +02:00
} else {
set top .
set pfx {}
}
git-gui: Save geometry before the window layout is damaged Because Tk does not assure us the order that it will process children in before it destroys the main toplevel we cannot safely save our geometry data during a "bind . <Destroy>" event binding. The geometry may have already changed as a result of a one or more children being removed from the layout. This was pointed out in gitk by Mark Levedahl, and patched over there by commit b6047c5a8166a71e01c6b63ebbb67c6894d95114. So we now also use "wm protocol . WM_DELETE_WINDOW" to detect when the window is closed by the user, and forward that close event to our main do_quit routine. Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2007-06-12 05:52:43 +02:00
if {$autodelete} {
wm protocol $top WM_DELETE_WINDOW "
[list delete_this $this]
[list destroy $top]
"
}
git-gui: Define a simple class/method system As most of the git-gui interface is based upon "meta-widgets" that need to carry around a good deal of state (e.g. console windows, browser windows, blame viewer) we have a good deal of messy code that tries to store this meta-widget state in global arrays, where keys into the array are formed from a union of a unique "object instance id" and the field name. This is a simple class system for Tcl that allows us to hide much of that mess by making Tcl do what it does best; process strings to manipulate its own code during startup. Each object instance is placed into its own namespace. The namespace is created when the object instance is created and the namespace is destroyed when the object instance is removed from the system. Within that namespace we place variables for each field within the class; these variables can themselves be scalar values or full-blown Tcl arrays. A simple class might be defined as: class map { field data field size 0 constructor {} { return $this } method set {name value} { set data($name) $value incr size } method size {} { return $size } ifdeleted { return 0 } } All fields must be declared before any constructors or methods. This allows our class to generate a list of the fields so it can properly alter the definition of the constructor and method bodies prior to passing them off to Tcl for definition with proc. A field may optionally be given a default/initial value. This can only be done for non-array type fields. Constructors are given full access to all fields of the class, so they can initialize the data values. The default values of fields (if any) are set before the constructor runs, and the implicit local variable $this is initialized to the instance identifier. Methods are given access to fields they actually use in their body. Every method has an implicit "this" argument inserted as its first parameter; callers of methods must be sure they supply this value. Some basic optimization tricks are performed (but not much). We try to only upvar (locally bind) fields that are accessed within a method, but we err on the side of caution and may upvar more than we need to. If a variable is accessed only once within a method and that access is by $foo (read) we avoid the upvar and instead use [set foo] to obtain the value. This is slightly faster as Tcl does not need to lookup the variable twice. We also offer some small syntatic sugar for interacting with Tk and the fileevent callback system in Tcl. If a field (say "foo") is used as "@foo" we insert instead the true global variable name of that variable into the body of the constructor or method. This allows easy binding to Tk textvariable options, e.g.: label $w.title -textvariable @title Proper namespace callbacks can also be setup with the special cb proc that is defined in each namespace. [cb _foo a] will invoke the method _foo in the current namespace, passing it $this as the first (implied) parameter and a as the second parameter. This makes it very simple to connect an object instance to a -command option for a Tk widget or to a fileevent readable or writable for a file channel. Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2007-05-09 01:54:05 +02:00
}
## auto_mkindex support for class/constructor/method
##
auto_mkindex_parser::command class {name body} {
variable parser
variable contextStack
set contextStack [linsert $contextStack 0 $name]
$parser eval [list _%@namespace eval $name] $body
set contextStack [lrange $contextStack 1 end]
}
auto_mkindex_parser::command constructor {name args} {
variable index
variable scriptFile
append index [list set auto_index([fullname $name])] \
[format { [list source [file join $dir %s]]} \
[file split $scriptFile]] "\n"
}
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