mirror of
https://gitlab.com/freepascal.org/lazarus/lazarus.git
synced 2025-04-11 13:28:04 +02:00
Docs: LCL/stdctrls. Restores documentation after reverting commit 9f577dc5.
This commit is contained in:
dsiders
parent
255bdd2bb0
commit
957d62af56
@ -10027,12 +10027,6 @@ mechanism.
|
||||
</element>
|
||||
|
||||
<!-- protected -->
|
||||
<element name="TButtonControl.FSkipOnChangeOnClick">
|
||||
<short>
|
||||
Member used to suppress calls to OnClicked in TCustomCheckBox.
|
||||
</short>
|
||||
</element>
|
||||
|
||||
<element name="TButtonControl.WMDefaultClicked">
|
||||
<short>Implements the default handler for the LM_CLICKED message.</short>
|
||||
</element>
|
||||
@ -10099,16 +10093,17 @@ Performs actions needed when a click message is handled for the control.
|
||||
</short>
|
||||
<descr>
|
||||
<p>
|
||||
<var>Click</var> is an overridden method in <var>TButtonControl</var>. It
|
||||
ensures that an OnChange notification occurs when needed. Click calls the
|
||||
<var>DoOnChange</var> method which signals the <var>OnEditingDone</var> and
|
||||
<var>OnChange</var> event handlers (when assigned).
|
||||
<var>Click</var> is an overridden method in <var>TButtonControl</var>. Click
|
||||
calls the <var>DoOnChange</var> method which signals the
|
||||
<var>OnEditingDone</var> and <var>OnChange</var> event handlers (when
|
||||
assigned).
|
||||
</p>
|
||||
<p>
|
||||
Click calls the inherited method prior to exit. The inherited method (in
|
||||
TControl) signals either the OnClick handler for the control or the OnExecute
|
||||
handler in the Action. OnClick is used when Action has not been assigned, or when OnClick contains a handler routine that differs from the one assigned to
|
||||
the OnExecute handler in the Action.
|
||||
TControl) signals either the OnClick event handler or the OnExecute handler
|
||||
in the Action. OnClick is used when Action has not been assigned, or when
|
||||
OnClick contains a handler routine that differs from the one assigned to the
|
||||
OnExecute handler in the Action.
|
||||
</p>
|
||||
<p>
|
||||
Click can be called in two different usage scenarios. If standard click
|
||||
@ -10119,19 +10114,10 @@ ControlStyle. This avoids duplicate click notifications when csClickEvents
|
||||
is enabled in ControlStyle and Click is handled when the WMLButtonUp method
|
||||
is executed.
|
||||
</p>
|
||||
<p>
|
||||
Click is overridden and re-implemented in the TCustomCheckBox descendent to
|
||||
provide support for Delphi VCL-compatible OnClick notifications.
|
||||
</p>
|
||||
</descr>
|
||||
<version>
|
||||
Modified in LCL 3.0 to support Delphi VCL-compatible OnClick notifications.
|
||||
</version>
|
||||
<seealso>
|
||||
<link id="TButtonControl.DoOnChange"/>
|
||||
<link id="TButtonControl.OnChange"/>
|
||||
<link id="TCustomCheckBox.Click"/>
|
||||
<link id="TCustomCheckBox.VCL_OnClick_Emulation"/>
|
||||
<link id="#lcl.controls.TControl.Click">TControl.Click</link>
|
||||
<link id="#lcl.controls.TControl.Action">TControl.Action</link>
|
||||
<link id="#lcl.controls.TControl.OnEditingDone">TControl.OnEditingDone</link>
|
||||
@ -11357,52 +11343,37 @@ handler. Use <var>ClicksDisabled</var> is control the event handler signalled.
|
||||
<descr>
|
||||
<p>
|
||||
<var>Click</var> is an overridden method in <var>TCustomCheckBox</var>. It
|
||||
performs actions needed when a mouse click or its keyboard equivalent occurs
|
||||
for the control.
|
||||
performs actions needed when the value in the Checked or State property is
|
||||
changed for the control, whether by mouse click or setting the value in
|
||||
program code.
|
||||
</p>
|
||||
<p>
|
||||
TCustomCheckBox re-implements the method from the TButtonControl ancestor to
|
||||
provide support for OnClick event notifications. The VCL_OnClick_Emulation
|
||||
class variable determines whether Delphi VCL-compatible OnClick event
|
||||
notifications are used. No actions are performed in the method when
|
||||
VCL_OnClick_Emulation is set to <b>True</b>. The OnClick event is signalled
|
||||
when the LM_CLICKED message is applied in the ancestor class
|
||||
(TButtonControl).
|
||||
ignore the mouse click event. It has an empty implementation, and does not call the inherited method.
|
||||
</p>
|
||||
<p>
|
||||
See VCL_OnClick_Emulation for more information about Delphi VCL-compatible
|
||||
OnClick event notifications.
|
||||
In TCustomCheckBox, the click action may be handled in two different ways.
|
||||
The action may be performed (in TControl) when the left mouse button is
|
||||
released and standard click events are enabled in ControlStyle. The click
|
||||
action may be performed in DoClickOnChange (by calling the inherited Click
|
||||
method) when the value in State is changed and ClicksDisabled is <b>False</b>.
|
||||
</p>
|
||||
<p>
|
||||
When VCL_OnClick_Emulation is <b>False</b>, the inherited Click method (in
|
||||
TButtonControl) is called to perform the actions needed. This includes
|
||||
signalling the OnChange event handler (when assigned and not already
|
||||
performed), and executing the OnClick handler in the control or the OnExecute
|
||||
handler from an assigned Action.
|
||||
</p>
|
||||
<p>
|
||||
Use the OnChange event handler to perform any actions needed when a new value
|
||||
is assigned to the State (or Checked) property.
|
||||
</p>
|
||||
<p>
|
||||
Use the OnClick event handler to perform any actions needed when mouse is clicked on the control.
|
||||
This avoids a duplicate click notification when csClickEvents is enabled in
|
||||
ControlStyle and Click is handled when the WMLButtonUp method is executed, or
|
||||
when the click is triggered by an associated Action.
|
||||
</p>
|
||||
</descr>
|
||||
<version>
|
||||
Modified in LCL 3.0 to support Delphi VCL-compatible OnClick notifications.
|
||||
</version>
|
||||
<seealso>
|
||||
<link id="TCustomCheckBox.VCL_OnClick_Emulation"/>
|
||||
<link id="TCustomCheckBox.State"/>
|
||||
<link id="TCustomCheckBox.OnChange"/>
|
||||
<link id="TCustomCheckBox.DoClickOnChange"/>
|
||||
<link id="TButtonControl.Checked"/>
|
||||
<link id="TButtonControl.ClicksDisabled"/>
|
||||
<link id="#lcl.controls.TControl.Click">TControl.Click</link>
|
||||
<link id="#lcl.controls.TControl.OnClick">TControl.OnClick</link>
|
||||
<link id="#lcl.controls.TControl.Action">TControl.Action</link>
|
||||
<link id="#lcl.controls.TControl.ControlState">TControl.ControlState</link>
|
||||
<link id="#lcl.controls.TControl.ControlStyle">TControl.ControlStyle</link>
|
||||
<link id="#lcl.controls.TControl.WMLButtonUp">TControl.WMLButtonUp</link>
|
||||
</seealso>
|
||||
</element>
|
||||
|
||||
@ -11650,142 +11621,6 @@ TextChanged calls the inherited method prior to exit.
|
||||
<short>Creation parameters updated in the method.</short>
|
||||
</element>
|
||||
|
||||
<element name="TCustomCheckBox.VCL_OnClick_Emulation">
|
||||
<short>
|
||||
Indicates whether the OnClick behavior used in the Delphi VCL is enabled for
|
||||
the control.
|
||||
</short>
|
||||
<descr>
|
||||
<p>
|
||||
<var>VCL_OnClick_Emulation</var> is a class variable which indicates whether
|
||||
the OnClick event is signalled using the behavior implemented in the Delphi
|
||||
VCL.
|
||||
</p>
|
||||
<p>
|
||||
For check box-style controls, there are two events of particular
|
||||
significance: OnChange and OnClick.
|
||||
</p>
|
||||
<p>
|
||||
In the LCL (Lazarus Component Library), these events are separate and
|
||||
distinct. OnChange occurs when the value in either the State or the Checked
|
||||
property is changed to a new value. This can result from assignment in
|
||||
program code, by clicking the mouse, or using a keyboard equivalent which
|
||||
causes the property to be updated. OnClick occurs only when the mouse or
|
||||
keyboard is used to interact with the control.
|
||||
</p>
|
||||
<p>
|
||||
In the Delphi VCL, the OnChange event does not exist. The OnClick handler is
|
||||
signalled when the value in State is changed and when the control is clicked.
|
||||
This class member allows use of Delphi handling for OnClick when the
|
||||
application has not accounted for the difference between the events and their
|
||||
usage in the LCL.
|
||||
</p>
|
||||
<p>
|
||||
When set to <b>True</b>, the OnClick event is signalled each time the State
|
||||
property is changed to a new value - including when the value was assigned
|
||||
instead of using the mouse or keyboard to perform the change. OnClick (and
|
||||
OnChange) are signalled only when a change in the State or Checked value
|
||||
occurs.
|
||||
</p>
|
||||
<p>
|
||||
The OnChange event in the VCL emulation mode has the same semantics and would
|
||||
be fired immediately before calling OnClick. This allows developers to
|
||||
migrate their applications from Delphi and gradually rework their code
|
||||
preparing for the behavior switch.
|
||||
</p>
|
||||
<p>
|
||||
For example, when a user clicks TRadioButton many times the event handler
|
||||
would only be called when the button transits to the selected state.
|
||||
Subsequent clicks on the already selected radio button would not result in
|
||||
additional OnClick event notifications. The OnChange event is also suppressed
|
||||
in this scenario.
|
||||
</p>
|
||||
<p>
|
||||
When set to <b>False</b>, LCL event handling is used. The OnChange event
|
||||
handler is signalled when the State or Checked property is changed to a new
|
||||
value, whether the change was caused by a user action or assignment in
|
||||
program code.
|
||||
</p>
|
||||
<p>
|
||||
The OnClick event handler in this mode is signalled each time the control is
|
||||
activated using the mouse, the keyboard, or by any other user action the
|
||||
operating system considers equal to clicking. It is signalled even when the
|
||||
State for the control is not changed. For radio buttons, repeated clicks on
|
||||
an already Checked control would result in an OnClick event notification for
|
||||
each mouse click.
|
||||
</p>
|
||||
<p>
|
||||
VCL_OnClick_Emulation does not require a class instance to access the member
|
||||
value. Changing the value affects all instances of the TCustomCheckBox
|
||||
control and descendants (like TToggleBox and TRadioButton) used in the
|
||||
application.
|
||||
</p>
|
||||
<p>
|
||||
For example:
|
||||
</p>
|
||||
<code>
|
||||
// enable Delphi OnClick behavior for all check boxes and descendants
|
||||
TCheckBox.VCL_OnClick_Emulation := True;
|
||||
|
||||
// enable LCL OnClick behavior for all check boxes and descendants
|
||||
TCheckBox.VCL_OnClick_Emulation := False;
|
||||
</code>
|
||||
<p>
|
||||
The default value for the member is <b>True</b> as assigned in the
|
||||
CreateClass class constructor. This enables Delphi VCL-compatible OnClick
|
||||
event notifications.
|
||||
</p>
|
||||
<p>
|
||||
VCL_OnClick_Emulation is used in the Click method to <b>prevent</b> calls to
|
||||
the inherited Click method when enabled. It is also used in the
|
||||
DoClickOnChange method to ensure that the inherited Click method is called
|
||||
when enabled and not already handled by an assigned Action.
|
||||
</p>
|
||||
</descr>
|
||||
<version>
|
||||
Added in LCL version 3.0.
|
||||
</version>
|
||||
<seealso>
|
||||
<link id="TButtonControl.Checked"/>
|
||||
<link id="TButtonControl.Click"/>
|
||||
<link id="TButtonControl.ClicksDisabled"/>
|
||||
<link id="TCustomCheckBox.State"/>
|
||||
<link id="TCustomCheckBox.OnChange"/>
|
||||
<link id="TCustomCheckBox.DoClickOnChange"/>
|
||||
<link id="TCustomCheckBox.CreateClass"/>
|
||||
<link id="#lcl.controls.TControl.OnClick">TControl.OnClick</link>
|
||||
<link id="#lcl.controls.TControl.Click">TControl.Click</link>
|
||||
</seealso>
|
||||
</element>
|
||||
|
||||
<element name="TCustomCheckBox.CreateClass">
|
||||
<short>
|
||||
Class constructor for the TCustomCheckBox class type.
|
||||
</short>
|
||||
<descr>
|
||||
<p>
|
||||
<var>CreateClass</var> is the class constructor for the
|
||||
<var>TCustomCheckBox</var> class type. It allows class variables and class
|
||||
properties to be initialized before the class type is used. The class
|
||||
constructor is <b>not</b> explicitly called in program code; it is called
|
||||
before entry into the initialization section for the <file>stdctrls.pp</file>
|
||||
unit.
|
||||
</p>
|
||||
<p>
|
||||
CreateClass ensures that the VCL_OnClick_Emulation class variable is set to
|
||||
<b>True</b> before an instance of the class is created. This enables Delphi
|
||||
VCL-compatible OnClick behavior in TCustomCheckBox and descendent classes
|
||||
like TCheckBox, TRadioButton and TToggleBox.
|
||||
</p>
|
||||
</descr>
|
||||
<version>
|
||||
Added in LCL version 3.0.
|
||||
</version>
|
||||
<seealso>
|
||||
<link id="TCustomCheckBox.VCL_OnClick_Emulation"/>
|
||||
</seealso>
|
||||
</element>
|
||||
|
||||
<element name="TCustomCheckBox.Create">
|
||||
<short>Constructor for the class instance.</short>
|
||||
<descr>
|
||||
@ -12042,50 +11877,6 @@ enables auto-sizing of the text displayed for the control instance.
|
||||
<element name="TCheckBox.OnChange" link="#lcl.stdctrls.TButtonControl.OnChange"/>
|
||||
<element name="TCheckBox.OnChangeBounds" link="#lcl.controls.TControl.OnChangeBounds"/>
|
||||
|
||||
<element name="TCheckBox.OnClick">
|
||||
<short>
|
||||
Event handler signalled when a mouse click occurs on the control.
|
||||
</short>
|
||||
<descr>
|
||||
<p>
|
||||
<var>OnClick</var> is a published <var>TNotifyEvent</var> property in
|
||||
<var>TCheckBox</var>. It contains the event handler signalled when a mouse
|
||||
click, or the keyboard equivalent, occurs when the control has focus. The
|
||||
actions performed for the click event can be specified in a user-supplied
|
||||
method, or by selecting an Action from an ActionList.
|
||||
</p>
|
||||
<p>
|
||||
OnClick is signalled (when assigned) from the Click method in the
|
||||
TButtonControl ancestor. It occurs when the event has not been handled in the
|
||||
descendant class and an Action has not been assigned using the ActionLink for
|
||||
the control. When Action is assigned, the Execute method in the ActionLink is
|
||||
called instead.
|
||||
</p>
|
||||
<p>
|
||||
TButtonControl descendants, like TCheckBox and TRadioButton, may signal the
|
||||
event handler when the value in State (or Checked) is changed. The
|
||||
VCL_OnClick_Emulation class variable enables this Delphi VCL-compatible
|
||||
behavior when it is set to <b>True</b>. When set to <b>False</b>, the event
|
||||
occurs only when mouse or keyboard is used to interact with the control.
|
||||
</p>
|
||||
<p>
|
||||
Use the OnChange event handler to perform actions needed when the value in
|
||||
the State property is changed.
|
||||
</p>
|
||||
</descr>
|
||||
<seealso>
|
||||
<link id="TCustomCheckBox.VCL_OnClick_Emulation"/>
|
||||
<link id="TCustomCheckBox.State"/>
|
||||
<link id="TButtonControl.Checked"/>
|
||||
<link id="TButtonControl.OnChange"/>
|
||||
<link id="#lcl.controls.TControl.OnClick">TControl.OnClick</link>
|
||||
<link id="#lcl.controls.TControl.Action">TControl.Action</link>
|
||||
<link id="#lcl.controls.TControl.ActionLink">TControl.ActionLink</link>
|
||||
<link id="#rtl.classes.TBasicAction">TBasicAction</link>
|
||||
<link id="#rtl.classes.TNotifyEvent">TNotifyEvent</link>
|
||||
</seealso>
|
||||
</element>
|
||||
|
||||
<element name="TCheckBox.OnContextPopup" link="#lcl.controls.TControl.OnContextPopup"/>
|
||||
<element name="TCheckBox.OnDragDrop" link="#lcl.controls.TControl.OnDragDrop"/>
|
||||
<element name="TCheckBox.OnDragOver" link="#lcl.controls.TControl.OnDragOver"/>
|
||||
@ -12209,51 +12000,7 @@ TabStop (<b>True</b>) and ParentColor (<b>False</b>) properties.
|
||||
<element name="TToggleBox.Font" link="#lcl.controls.TControl.Font"/>
|
||||
<element name="TToggleBox.Hint" link="#lcl.controls.TControl.Hint"/>
|
||||
<element name="TToggleBox.OnChange" link="#lcl.stdctrls.TButtonControl.OnChange"/>
|
||||
|
||||
<element name="TToggleBox.OnClick">
|
||||
<short>
|
||||
Event handler signalled when the mouse is clicked on the control.
|
||||
</short>
|
||||
<descr>
|
||||
<p>
|
||||
<var>OnClick</var> is a published <var>TNotifyEvent</var> in
|
||||
<var>TToggleBox</var>. It contains the event handler signalled when a mouse
|
||||
click, or the keyboard equivalent, occurs when the control has focus. The
|
||||
actions performed for the click event can be specified in a user-supplied
|
||||
method, or by selecting an Action from an ActionList.
|
||||
</p>
|
||||
<p>
|
||||
OnClick is signalled (when assigned) from the Click method in the
|
||||
TButtonControl ancestor. It occurs when the event has not been handled in the
|
||||
descendant class and an Action has not been assigned using the ActionLink for
|
||||
the control. When Action is assigned, the Execute method in the ActionLink is
|
||||
called instead.
|
||||
</p>
|
||||
<p>
|
||||
TButtonControl descendants, like TCheckBox and TToggleBox, may signal the
|
||||
event handler when the value in State (or Checked) is changed. The
|
||||
VCL_OnClick_Emulation class variable enables this Delphi VCL-compatible
|
||||
behavior when it is set to <b>True</b>. When set to <b>False</b>, the event
|
||||
occurs only when mouse or keyboard is used to interact with the control.
|
||||
</p>
|
||||
<p>
|
||||
Use the OnChange event handler to perform actions needed when the value in
|
||||
the State property is changed.
|
||||
</p>
|
||||
</descr>
|
||||
<seealso>
|
||||
<link id="TCustomCheckBox.VCL_OnClick_Emulation"/>
|
||||
<link id="TCustomCheckBox.State"/>
|
||||
<link id="TButtonControl.Checked"/>
|
||||
<link id="TButtonControl.OnChange"/>
|
||||
<link id="#lcl.controls.TControl.OnClick">TControl.OnClick</link>
|
||||
<link id="#lcl.controls.TControl.Action">TControl.Action</link>
|
||||
<link id="#lcl.controls.TControl.ActionLink">TControl.ActionLink</link>
|
||||
<link id="#rtl.classes.TBasicAction">TBasicAction</link>
|
||||
<link id="#rtl.classes.TNotifyEvent">TNotifyEvent</link>
|
||||
</seealso>
|
||||
</element>
|
||||
|
||||
<element name="TToggleBox.OnClick" link="#lcl.controls.TControl.OnClick"/>
|
||||
<element name="TToggleBox.OnContextPopup" link="#lcl.controls.TControl.OnContextPopup"/>
|
||||
<element name="TToggleBox.OnDragDrop" link="#lcl.controls.TControl.OnDragDrop"/>
|
||||
<element name="TToggleBox.OnDragOver" link="#lcl.controls.TControl.OnDragOver"/>
|
||||
@ -12522,51 +12269,7 @@ The default value for the property is <b>True</b> in <var>TRadioButton</var>.
|
||||
<element name="TRadioButton.Hint" link="#lcl.controls.TControl.Hint"/>
|
||||
<element name="TRadioButton.OnChange" link="#lcl.stdctrls.TButtonControl.OnChange"/>
|
||||
<element name="TRadioButton.OnChangeBounds" link="#lcl.controls.TControl.OnChangeBounds"/>
|
||||
|
||||
<element name="TRadioButton.OnClick">
|
||||
<short>
|
||||
Event handler signalled when the mouse is clicked on the control.
|
||||
</short>
|
||||
<descr>
|
||||
<p>
|
||||
<var>OnClick</var> is a published <var>TNotifyEvent</var> in
|
||||
<var>TRadioButton</var>. It contains the event handler signalled when a mouse
|
||||
click, or the keyboard equivalent, occurs when the control has focus. The
|
||||
actions performed for the click event can be specified in a user-supplied
|
||||
method, or by selecting an Action from an ActionList.
|
||||
</p>
|
||||
<p>
|
||||
OnClick is signalled (when assigned) from the Click method in the
|
||||
TButtonControl ancestor. It occurs when the event has not been handled in the
|
||||
descendant class and an Action has not been assigned using the ActionLink for
|
||||
the control. When Action is assigned, the Execute method in the ActionLink is
|
||||
called instead.
|
||||
</p>
|
||||
<p>
|
||||
TButtonControl descendants, like TCheckBox and TToggleBox, may signal the
|
||||
event handler when the value in State (or Checked) is changed. The
|
||||
VCL_OnClick_Emulation class variable enables this Delphi VCL-compatible
|
||||
behavior when it is set to <b>True</b>. When set to <b>False</b>, the event
|
||||
occurs only when mouse or keyboard is used to interact with the control.
|
||||
</p>
|
||||
<p>
|
||||
Use the OnChange event handler to perform actions needed when the value in
|
||||
the State property is changed.
|
||||
</p>
|
||||
</descr>
|
||||
<seealso>
|
||||
<link id="TCustomCheckBox.VCL_OnClick_Emulation"/>
|
||||
<link id="TCustomCheckBox.State"/>
|
||||
<link id="TButtonControl.Checked"/>
|
||||
<link id="TButtonControl.OnChange"/>
|
||||
<link id="#lcl.controls.TControl.OnClick">TControl.OnClick</link>
|
||||
<link id="#lcl.controls.TControl.Action">TControl.Action</link>
|
||||
<link id="#lcl.controls.TControl.ActionLink">TControl.ActionLink</link>
|
||||
<link id="#rtl.classes.TBasicAction">TBasicAction</link>
|
||||
<link id="#rtl.classes.TNotifyEvent">TNotifyEvent</link>
|
||||
</seealso>
|
||||
</element>
|
||||
|
||||
<element name="TRadioButton.OnClick" link="#lcl.controls.TControl.OnClick"/>
|
||||
<element name="TRadioButton.OnContextPopup" link="#lcl.controls.TControl.OnContextPopup"/>
|
||||
<element name="TRadioButton.OnDragDrop" link="#lcl.controls.TControl.OnDragDrop"/>
|
||||
<element name="TRadioButton.OnDragOver" link="#lcl.controls.TControl.OnDragOver"/>
|
||||
|
||||
Loading…
Reference in New Issue
Block a user