- Destroy is the overridden destructor for the class instance. It ensures that the Flags for the node are updated to include the value nfDestroying. If the OwnerDocument for the node has a hash table for node IDs, its RemoveID method is called to remove the current class isntance. Destroy frees resources allocated for the Attributes property, and calls the inherited destructor prior to exit. + Destroy is the overridden destructor for the class instance. It ensures that the Flags for the node are updated to include the value nfDestroying. If the OwnerDocument for the node has a hash table for node IDs, its RemoveID method is called to remove the current class instance. Destroy frees resources allocated for the Attributes property, and calls the inherited destructor prior to exit.
+ TContainedAction is a TBasicAction descendant which allows an action to be given a category, and grouped with related actions. It provides additional properties and methods used to assign an action to the category and an associated list of actions. These values are used at design-time in the Action List editor. +
++ TContainedAction is the ancestor for the TCustomAction class. +
++ ReadState is an overridden method in TContainedAction used to read values for the class instance during LCL component streaming. It calls the inherited method to read properties and child components using the specified TReader class instance. When the Parent in Reader is a TCustomActionList instance, it is stored in the ActionList property. +
++ SetParentComponent is an overridden method used to set the property in the class instance which contains the parent component. It re-implements the method from the ancestor class. +
++ In TContainedAction, it sets the ActionList property to the value in AParent when AParent is derived from TCustomActionList. +
+- If you call Destroy for an object which hasn't being initialized yet it will generate an error. Always use the Free method to deallocate objects, because it verifies if object variable doesn´t contain the value nil. + Destroy is the overridden destructor for the class instance. When ActionList has been assigned, its RemoveAction method is called to delete the current class instance.
- Take the following precautions when creating your own Destroy method: + Destroy calls the inherited method to free the class instance and unregister any action link clients.
-+ Execute is an overridden method in TContainedAction. It checks for an available OnExecute event handlers in ActionList, the Application singleton, and the class instance. If an OnExecute event handler is not found, it posts a CM_ACTIONEXECUTE control message to the application. +
++ GetParentComponent is an overridden method used to get the property in the class instance which is the parent component for the class instance. It re-implements the method from the ancestor class. +
++ In TContainedAction, it gets the value in the ActionList property (when assigned) or calls the inherited method. +
++ HasParent is an overridden method in TContainedAction. It checks for an assigned value in the ActionList property, and sets the return value to True when assigned. Otherwise, the inherited method is called to get the return value. +
++ TActionListEnumerator implements an enumerator for TContainedAction values stored in TCustomActionList. It allows navigation of values in the Actions property using the "for .. in" loop syntax. TActionListEnumerator is the type returned from the TCustomActionList.GetEnumerator method. +
++ Stores the value passed in AList to the member variable for the Actions property. Sets the value for the internal position member to -1. +
++ Current is a read-only TContainedAction property with the current value for the enumerator. The property value is retrieved from Actions using the position in an internal member. +
++ Arguments passed to the event handler include the Action for the notification and a return value that indicates if the action was executed. +
++ TActionEvent is the type used for the OnExecute and OnUpdate properties in TCustomActionList. +
++ TActionListState is the type used for the State property in TCustomActionList. +
++ Sets the parent component for the action, and adds the value to the internal list for the component. Raises an Exception if the Action has already been added to the action list. +
++ Change signals the OnChange event handler (when assigned) to perform user-specified operations for the action list. Change also visits each of the Actions in the action list, and calls its Change method to signal the OnChange event handler supplied at the action level. It calls the OwnerFormDesignerModified routine at design-time to notify the form designer of the change to the action list. +
++ Change is called when a new TCustomImageList value is assigned to the Images property in the action list. +
++ Calls the inherited method on entry. Sets Images to Nil when the image list is removed from the component. Calls the RemoveAction method when AComponent is a TContainedAction instance removed from the component. +
++ SetChildOrder is an overridden method in TCustomActionList. It sets the ordinal position for the action in Component to the value specified in Order. The IndexOf method in Actions is called to get the current position for Component. The value in Order is assigned to the Index property in the TContainedAction when it exists in Actions. No actions are performed in the method when Component is not stored in the Actions for the action list. +
+ExecuteAction checks whether Action handles the current component, and if yes, calls the ExecuteAction method, passing itself as a parameter. The function returns True if the action handles the current component.
UpdateAction checks whether Action handles the current component, and if yes, calls the UpdateTarget method, passing itself as a parameter. The function returns True if the action handles the current component.
- To use an ActionList, click on the icon on the IDE Standard Components toolbar, then click anywhere on the main form and an ActionList icon will appear. It doesn't matter where you position it, because it is not visible at run-time. + To use an ActionList, click on the icon on the IDE Standard Components toolbar, then click anywhere on the main form and an ActionList icon will appear. It does not matter where you position it, because it is not visible at run-time.
You can add, remove or modify actions on the list by right-clicking on the ActionList icon on the form editor and then choosing "Edit action list...", or by double-clicking on the icon with the left mouse button. This will open the "Action List Editor". @@ -584,7 +760,7 @@ The TActionList class introduces very few properties of its own, but inherits a lot from its ancestor, TCustomActionList, and related components TAction, TCustomAction, TContainedAction and - TBasicAction. + TBasicAction.
Each entry in the ActionList appears in the Object Inspector as an instance of TAction, and its properties are accessible and modifiable from the Object Inspector. @@ -685,23 +861,22 @@
AssignTo is the generic function to assign the class' contents to another class. This method must be overridden by descendent classes to actually assign the content of the source instance to the destination instance.
@@ -872,21 +1050,29 @@
+ SetName is overridden in TCustomAction. It calls the inherited method to ensure that Value is a valid identifier name for the component and its owner (when assigned). The inherited method may raise an EComponentError exception if the name in value is not a valid identifier. The new property value is also assigned to the Caption property in the action when the number of control clients is 0. +
++ Execute is an overridden method in TCustomAction. It checks the State for the ActionList to enusre that it is not suspended. No actions are performed in the method when ActionList.State contains a value other than asNormal. +
++ Execute calls Update to signal an available OnUpdate event handler in the ActionList, the Application singleton, or the class instance. It toggles the value in the Checked property when AutoCheck is enabled. The inherited Execute method is called when the class instance is Enabled. +
++ The return value is True if the action was executed in the method. +
+
@@ -1127,13 +1331,18 @@
OnUpdate is the event triggered when the application is idle, and the action is being updated. The OnUpdate event can be used to set the state of the action, for instance disable it if the action cannot be executed at this point in time.
-+ Calls the Clear method for the protected Tabs property in the TCustomTabControl ancestor. +
+@@ -6020,20 +6020,26 @@
+ Loaded is an overridden method in TCustomTimer. It calls the inherited method on entry to remove csLoading from the ComponentState property. +
++ Loaded calls UpdateTimer to re-create the timer handle and signal event event handlers as needed for the Enabled property in the timer. An EOutOfResources exception is raised (in UpdateTimer) if a timer handle cannot be allocated in the widgetset class. +
++ WSRegisterClass is a class method used to register the component class with the widgetset. +
++ It is overridden in TDBImage to ensure that the class is registered only once. No actions are performed in the method if the class has already been registered with the widgetset. It calls the inherited method to register ancestor image classes. +
++ TDBImage calls RegisterPropertyToSkip to exclude the Picture property during LCL component streaming. TDBImage loads its Picture data from the data set, and not from an LFM resource. Picture was removed in Lazarus version 0.9.29. +
+- Create is the constructor for the class instance, and calls the inherited constructor on entry. Create stores parameter values to the members used for the associated grid and the map used in the class isntance. + Create is the constructor for the class instance, and calls the inherited constructor on entry. Create stores parameter values to the members used for the associated grid and the map used in the class instance.
+ Tag can be used to store an integer value in the component. This value is streamed together with all other published properties. It can be used for instance to quickly identify a component in an event handler. +
+