Undo Mechanism - Revision history

Tuukka Lehtonen: /* Undo and redo handling in the Simantics workbench */

2015-10-15T10:48:50Z

Undo and redo handling in the Simantics workbench

@@ Line 40: / Line 40: @@
 * Do the operation.
 * Check from ''Teamwork'' / ''Graph History'' view which change sets have been created and that they are commented properly.
 == Related Documents ==
 * [[Undo and Redo]] - internals of the mechanism.

Tuukka Lehtonen at 12:17, 23 May 2012

2012-05-23T12:17:11Z

← Older revision		Revision as of 12:17, 23 May 2012
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	[[Category: Database Development]]		[[Category: Database Development]]

	This page documents a simple global non contextual undo/redo mechanism.		This page documents a simple global non-contextual undo/redo mechanism.

	== Mechanism ==		== Mechanism ==

	Database client keeps a global list of undoable/redoable operations. Operations are added to undo list during commit. Each commit creates a change set to server which defines the changes to resource values and statements. Change set also contains metadata for interpreting the change. The metadata format is defined by client and the server can not read or interpret it. Each operation has unique change set identifier. Sequential operations are tagged as combined by giving them the same operation id. All operations with same id will be treated as single undoable/redoable operation. ~~Database~~ client ~~groups~~ all change sets ~~created within one write request as~~ one operation.		Database client keeps a global list of undoable/redoable operations. Operations are added to undo list during commit. Each commit creates a change set to server which defines the changes to resource values and statements. Change set also contains metadata for interpreting the change. The metadata format is defined by client and the server can not read or interpret it. Each operation has a unique change set identifier. Sequential operations are tagged as combined by giving them the same operation id. All operations with same id will be treated as single undoable/redoable operation.

			=== Combining write requests ===

			Currently there is only one way to combine several database write requests into a single operation.

			Normally an operation is created out of each separate write transaction. This happens when write transactions are initiated by invoking '''Session.async/asyncRequest'''. To combine a separate write transaction into a single operation, the write request must be initiated from within the write transaction using any '''WriteGraph.async/asyncRequest''' interface methods. The database client will group all write transaction change sets initiated like this into one operation.

	== Undo and redo handling in the Simantics workbench ==		== Undo and redo handling in the Simantics workbench ==

Tuukka Lehtonen: /* Undo and redo handling in the Simantics workbench */

2011-09-15T23:43:51Z

Undo and redo handling in the Simantics workbench

← Older revision		Revision as of 23:43, 15 September 2011
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	== Undo and redo handling in the Simantics workbench ==		== Undo and redo handling in the Simantics workbench ==

	If '''org.eclipse.ui.edit.undo''' and '''org.eclipse.ui.edit.redo''' commands are bound to handlers ~~Diagram~~{Undo,Redo}Handler then the undo/redo mechanism is activated. The handlers undo/redo one operation from the global undo/redo lists with each button press. It is desirable that each developer who develops requests that modify the graph comment their changes as shown by thefollowing example.		If '''org.eclipse.ui.edit.undo''' and '''org.eclipse.ui.edit.redo''' commands are bound to handlers '''Session{Undo,Redo}Handler''' then the undo/redo mechanism is activated. The handlers undo/redo one operation from the global undo/redo lists with each button press. It is desirable that each developer who develops requests that modify the graph comment their changes as shown by thefollowing example.

	<div style="background-color:#f8f8f8; border: 1px dashed #cccccc; padding: 1ex; margin-left:2em; margin-top: 1em; margin-bottom:1em;">		<div style="background-color:#f8f8f8; border: 1px dashed #cccccc; padding: 1ex; margin-left:2em; margin-top: 1em; margin-bottom:1em;">

Tuukka Lehtonen at 22:59, 15 September 2011

2011-09-15T22:59:03Z

← Older revision		Revision as of 22:59, 15 September 2011
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			[[Category: Database Development]]

	This page documents a simple global non contextual undo/redo mechanism.		This page documents a simple global non contextual undo/redo mechanism.

Tuukka Lehtonen: /* Undo and redo handling in the Simantics workbench */

2011-09-15T21:43:49Z

Undo and redo handling in the Simantics workbench

← Older revision		Revision as of 21:43, 15 September 2011
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	<div style="background-color:#f8f8f8; border: 1px dashed #cccccc; padding: 1ex; margin-left:2em; margin-top: 1em; margin-bottom:1em;">		<div style="background-color:#f8f8f8; border: 1px dashed #cccccc; padding: 1ex; margin-left:2em; margin-top: 1em; margin-bottom:1em;">
	<syntaxhighlight lang="java">		<syntaxhighlight lang="java">
	session.~~syncRequest~~(new WriteRequest() {		session.sync(new WriteRequest() {
	@Override		@Override
	public void perform(WriteGraph graph) throws DatabaseException {		public void perform(WriteGraph graph) throws DatabaseException {

Tuukka Lehtonen: /* Undo and redo handling in the Simantics workbench */

2011-09-15T21:43:15Z

Undo and redo handling in the Simantics workbench

← Older revision		Revision as of 21:43, 15 September 2011
Line 9:		Line 9:
	If '''org.eclipse.ui.edit.undo''' and '''org.eclipse.ui.edit.redo''' commands are bound to handlers Diagram{Undo,Redo}Handler then the undo/redo mechanism is activated. The handlers undo/redo one operation from the global undo/redo lists with each button press. It is desirable that each developer who develops requests that modify the graph comment their changes as shown by thefollowing example.		If '''org.eclipse.ui.edit.undo''' and '''org.eclipse.ui.edit.redo''' commands are bound to handlers Diagram{Undo,Redo}Handler then the undo/redo mechanism is activated. The handlers undo/redo one operation from the global undo/redo lists with each button press. It is desirable that each developer who develops requests that modify the graph comment their changes as shown by thefollowing example.

	<~~pre~~>		<div style="background-color:#f8f8f8; border: 1px dashed #cccccc; padding: 1ex; margin-left:2em; margin-top: 1em; margin-bottom:1em;">
			<syntaxhighlight lang="java">
	session.syncRequest(new WriteRequest() {		session.syncRequest(new WriteRequest() {
	@Override		@Override
Line 24:		Line 25:
	}		}
	});		});
	</~~pre~~>		</syntaxhighlight>
			</div>

	You can test your operations using the following procedure:		You can test your operations using the following procedure:

Tuukka Lehtonen: /* Undo and redo handling in the Simantics workbench */

2011-09-15T21:38:12Z

Undo and redo handling in the Simantics workbench

← Older revision		Revision as of 21:38, 15 September 2011
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	== Undo and redo handling in the Simantics workbench ==		== Undo and redo handling in the Simantics workbench ==

	If '''org.eclipse.ui.edit.undo''' and '''org.eclipse.ui.edit.redo''' commands are bound to handlers ~~DiagramUndo/RedoHandler~~ then the undo/redo mechanism is activated. The handlers undo/redo one operation from the global undo/redo lists with each button press. It is desirable that each developer who develops requests that modify the graph comment their changes as shown by thefollowing example.		If '''org.eclipse.ui.edit.undo''' and '''org.eclipse.ui.edit.redo''' commands are bound to handlers Diagram{Undo,Redo}Handler then the undo/redo mechanism is activated. The handlers undo/redo one operation from the global undo/redo lists with each button press. It is desirable that each developer who develops requests that modify the graph comment their changes as shown by thefollowing example.

	<pre>		<pre>

Tuukka Lehtonen: /* Undo and redo handling */

2011-09-15T21:37:56Z

Undo and redo handling

← Older revision		Revision as of 21:37, 15 September 2011
Line 5:		Line 5:
	Database client keeps a global list of undoable/redoable operations. Operations are added to undo list during commit. Each commit creates a change set to server which defines the changes to resource values and statements. Change set also contains metadata for interpreting the change. The metadata format is defined by client and the server can not read or interpret it. Each operation has unique change set identifier. Sequential operations are tagged as combined by giving them the same operation id. All operations with same id will be treated as single undoable/redoable operation. Database client groups all change sets created within one write request as one operation.		Database client keeps a global list of undoable/redoable operations. Operations are added to undo list during commit. Each commit creates a change set to server which defines the changes to resource values and statements. Change set also contains metadata for interpreting the change. The metadata format is defined by client and the server can not read or interpret it. Each operation has unique change set identifier. Sequential operations are tagged as combined by giving them the same operation id. All operations with same id will be treated as single undoable/redoable operation. Database client groups all change sets created within one write request as one operation.

	== Undo and redo handling ==		== Undo and redo handling in the Simantics workbench ==

	If ~~Ctrl-Z~~ and ~~Ctrl-Y keys~~ are ~~mapped~~ to ~~call~~ DiagramUndo/RedoHandler then the undo/redo mechanism is activated. The handlers undo/redo one operation from the global undo/redo lists with each button press. It is desirable that each developer who develops requests that modify the graph comment their changes as shown by thefollowing example.		If '''org.eclipse.ui.edit.undo''' and '''org.eclipse.ui.edit.redo''' commands are bound to handlers DiagramUndo/RedoHandler then the undo/redo mechanism is activated. The handlers undo/redo one operation from the global undo/redo lists with each button press. It is desirable that each developer who develops requests that modify the graph comment their changes as shown by thefollowing example.

	<pre>		<pre>

Tuukka Lehtonen: /* Undo and redo handling */

2011-09-15T21:36:28Z

Undo and redo handling

← Older revision		Revision as of 21:36, 15 September 2011
Line 7:		Line 7:
	== Undo and redo handling ==		== Undo and redo handling ==

	If ~~ctrl~~-z and ~~crtl~~-y keys are mapped to call DiagramUndo/RedoHandler then the undo/redo mechanism is activated. The handlers undo/redo one operation from the global undo/redo lists with each button press. It is desirable that each developer who develops requests that modify the graph comment their changes as shown by thefollowing example.		If Ctrl-Z and Ctrl-Y keys are mapped to call DiagramUndo/RedoHandler then the undo/redo mechanism is activated. The handlers undo/redo one operation from the global undo/redo lists with each button press. It is desirable that each developer who develops requests that modify the graph comment their changes as shown by thefollowing example.

	<pre>		<pre>

Tuukka Lehtonen: /* Undo and redo handling */

2011-09-15T21:33:47Z

Undo and redo handling

← Older revision		Revision as of 21:33, 15 September 2011
Line 7:		Line 7:
	== Undo and redo handling ==		== Undo and redo handling ==

	If ~~crtl~~-z and crtl-y keys are mapped to call DiagramUndo/RedoHandler then the undo/redo mechanism is activated. The handlers undo/redo one operation from the global undo/redo lists with each button press. It is desirable that each developer who develops requests that modify the graph comment ~~them~~ as ~~the following~~ example ~~shows~~.		If ctrl-z and crtl-y keys are mapped to call DiagramUndo/RedoHandler then the undo/redo mechanism is activated. The handlers undo/redo one operation from the global undo/redo lists with each button press. It is desirable that each developer who develops requests that modify the graph comment their changes as shown by thefollowing example.

	<pre>		<pre>
Line 26:		Line 26:
	</pre>		</pre>

	~~This~~ can ~~be done by~~ the following procedure:		You can test your operations using the following procedure:

	* Do the operation.		* Do the operation.
	* Check from ~~graph history~~ view which change sets have been created and that they are commented properly.		* Check from ''Teamwork'' / ''Graph History'' view which change sets have been created and that they are commented properly.

	== Related Documents ==		== Related Documents ==

	* [[Undo and Redo]] - internals of the mechanism.		* [[Undo and Redo]] - internals of the mechanism.