VCF::Action Class Reference
The
Action class is used to represent an "action" that gets performed because of some event from the UI, such as clicking a menu item or button.
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#include <vcf/ApplicationKit/Action.h>
Inheritance diagram for VCF::Action:
List of all members.
Detailed Description
The
Action class is used to represent an "action" that gets performed because of some event from the UI, such as clicking a menu item or button.
An Action also allows you to consolidate multiple event handlers for menu items, buttons, etc, and their associated code to update their UI state in relation to the application's state. An Action has one or more targets that get notified for update events. Any of these targets can also cause the action to be executed or "performed".
An example of how this might be useful:
Consider an application that has three UI elements, a button, a toolbar item, and a menu item. Clicking the menu item, toolbar item, or button all cause some change of state in the application. Without using actions, you would have to write 3 individual event handlers for the "click" events of the menu item, button, and toolbar item, as well as separate ui updating code. If you use an action, you simply add all three items as targets to the action, and then write a single handler that's attached to the action's Performed delegate, and another event handler that is attached to the action's Update delegate. The framework then takes care of the rest, and clicking the button, menu item, or toolbar item will all cause event handler attached to the action's Performed delegate to get called, and each UI element will in turn be updated as specified by event handler attached to the action's Update delegate.
- Event Delegates for this class:
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Member Enumeration Documentation
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- Enumerator:
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| UpdateEvent |
This event type is used when the update method is invoked. |
| ActionPerformedEvent |
This is used when an action event is fired. |
| AcceleratorChanged |
This is used when the action's accelerator is changed, specifically by the method setAcceleratorKey(). |
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Constructor & Destructor Documentation
| VCF::Action::Action |
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const String & |
name |
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| virtual VCF::Action::~Action |
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[virtual] |
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Member Function Documentation
| void VCF::Action::addTarget |
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Component * |
target |
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adds a target to the action
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Returns the accelerator for the action item.
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Returns the event handler used to trigger the action's perform() method when the appropriate key combination is pressed.
If no event handler exists at the time of this call, a new instance will be created. |
| uint32 VCF::Action::getTargetCount |
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returns a count of the number of targets attached to this action.
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returns an enumerator of all the targets currently attached to this action.
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| void VCF::Action::onAccelerator |
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KeyboardEvent * |
e |
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the default event handler for the accelerator associated to this action.
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| void VCF::Action::perform |
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Event * |
event = NULL |
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This is called to execute the action.
An action performed event will be fired off to all the event handlers attached to the Performed delegate. |
| void VCF::Action::removeTarget |
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Component * |
target |
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removes a target from the action.
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Sets the acclerator object for this action item.
If one already exists then it is removed. To ensure that any targets of this action are properly updated, the action creates a Event instance, sets it's event type to Action::AcceleratorChanged, loops through all it's targets, and then calls each target's handleEvent() method passing in the event instance. Targets should respond accordingly to this event if it makes sense. |
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This sets the accelerator key object for the action item.
If one already exists it is removed for this action item. The accelerator is assigned the key code and modifier mask passed in, and is given a default event handler which calls the action item's perform method. An action may have only one accelerator associated with it at any given time. Internally this method creates a new AcceleratorKey isntance and then calls the setAcceleratorKey( AcceleratorKey* ) method. See this method's documentation for more details. - See also:
- setAcceleratorKey
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| void VCF::Action::update |
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This is called by a target (or the framework itself) to tell the action to fire off an update event to all the actions targets.
First an Update event is fired in order to let the application to set, in the event(s) handler(s) of this action, the desired state for the ActionEvent ( e.g. enabled or not, checked or not. Then the update ActionEvent is fired off to all the actions targets. The enabled state of the accelerator associated to this action, if any, is also updated accordingly. - See also:
- ActionEvent
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Member Data Documentation
The documentation for this class was generated from the following file:
