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Actions, menu items, toolbars and toolboxes |
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=========================================== |
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The GTK+ structure is like this:: |
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UIManager |
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ActionGroup |
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Action |
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The do_activate signal is emitted when an action is activated. |
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Where it should lead: |
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* Actions should be coded closer to the object their working on |
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- main actions - not dependent on GUI components (load/save/new/quit) |
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- main actions dependent on GUI component (sub-windows, console) |
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- Item actions, act either on a diagram, the selected or focused item |
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or no item. |
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- diagram actions (zoom, grid) work on active diagram (tab) |
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- menus and actions for diagram items through adapters |
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* Actions should behave more like adapters. E.g. when a popup menu is created |
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for an Association item, the menu actions should present themselves in the |
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context of that menu item (with toggles set right) |
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- Could be registered as adapters with a name. |
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* Each window has it's own action group (every item with a menu?) |
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* One toplevel UIManager per window or one per application/gui_manager? |
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* Normal actions can be modeled as functions. If an action is sensitive or |
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visible depends on the state in the action. Hence we require the update() |
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method. |
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* create services for for "dynamic" menus (e.g. recent files/stereotypes) |
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Solution for simple actions |
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--------------------------- |
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For an action to actually be useful a piece of menu xml is needed. |
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Hence an interface IActionProvider has to be defined:: |
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class IActionProvider(interface.Interface): |
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menu_xml = interface.Attribute("The menu XML") |
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action_group = interface.Attribute("The accompanying ActionGroup") |
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Support for actions can be arranged by decorating actions with an @action |
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decorator and let the class create an ActionGroup using some |
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actionGroup factory function (no inheritance needed here). |
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Note that ActionGroup is a GTK class and should technically only be used in the |
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gaphor.ui package. |
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Autonom controllers can be defined, which provide a piece of functionality. |
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They can register handlers in order to update their state. |
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Maybe it's nice to configure those through the egg-info system. I suppose |
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gaphor.service will serve well (as they need to be initialized anyway) |
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==> also inherit IActionProvider from IService? |
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[gaphor.services] |
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xx = gaphor.actions.whatever:SomeActionProviderClass |
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Solution for context sensitive menus |
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------------------------------------ |
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Context sensitive menus, such as popup menus, should be generated and switched |
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on and off on demand. |
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Technically they should be enabled through services/action-providers. |
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It becomes even tougher when popup menu's should act on parts of a diagram item |
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(such as association ends). This should be avoided. It may be a good idea to |
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provide such functionality through a special layer on the canvas, by means of |
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some easy clickable buttons around the "hot spot" (we already have something |
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like that for text around association ends). |
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Scheme: |
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1. User selects an item and presses the rigth mouse button: a popup menu |
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should be displayed. |
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2. find the actual item (this may be a composite item of the element drawn). |
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Use an IItemPicker adapter for that (if no such interface is available, |
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use the item itself). |
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2. Find a IActionProvider adapters for the selected (focused) item. |
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3. update the popup menu context (actions) for the selected item. |
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