Development/Tutorials/Session Management - Revision history

AnneW at 18:32, 15 July 2012

2012-07-15T18:32:32Z

Icwiener: Fix syntax highlighting.

2011-06-27T13:47:53Z

Fix syntax highlighting.

Urwald: polishing style

2010-10-13T07:47:56Z

polishing style

Show changes

Urwald at 10:05, 12 December 2009

2009-12-12T10:05:14Z

Urwald: adjusting values of TutorialBrowser

2009-04-11T14:34:35Z

adjusting values of TutorialBrowser

Urwald: refactorying

2009-04-11T08:52:09Z

refactorying

Urwald at 05:57, 11 April 2009

2009-04-11T05:57:39Z

Urwald at 07:41, 6 April 2009

2009-04-06T07:41:31Z

Urwald at 07:40, 6 April 2009

2009-04-06T07:40:40Z

Urwald: unclear explication corrected

2009-04-05T19:44:20Z

unclear explication corrected

← Older revision		Revision as of 18:32, 15 July 2012
Line 1:		Line 1:
−	~~{{Template:I18n/Language Navigation Bar\|Development/Tutorials/Session Management}}~~	+

	{{TutorialBrowser\|		{{TutorialBrowser\|

@@ Line 80: / Line 80: @@
 application windows with something like this:
-<code cppqt>
+<syntaxhighlight lang="cpp-qt">
 KApplication app;
 if ( app.isSessionRestored() ) {
@@ Line 94: / Line 94: @@
+}
 return app.exec();
-</code>
+</syntaxhighlight>
 [http://api.kde.org/4.x-api/kdelibs-apidocs/kdeui/html/kmainwindow_8h.html#88ce427e39f425eefa5a94d746eb2bed kRestoreMainWindows<>()] will create (on the heap) as many instances of your main windows as have existed in the last session and call [http://api.kde.org/4.x-api/kdelibs-apidocs/kdeui/html/classKMainWindow.html#46e01bd1aa6d488f1be2a5010030efb2 KMainWindow::restore()] with the correct arguments. Note that also QWidget::show() is called implicitly.
@@ Line 105: / Line 105: @@
 derived from [http://api.kde.org/4.x-api/kdelibs-apidocs/kdeui/html/classKMainWindow.html KMainWindow], of course) within one application. Imagine you have three classes of main windows: childMW1, childMW2 and childMW3:
-<code cppqt>
+<syntaxhighlight lang="cpp-qt">
 KApplication app;
 if ( app.isSessionRestored() ) {
@@ Line 125: / Line 125: @@
+}
 return app.exec();
-</code>
+</syntaxhighlight>
 Currently, kdelibs provides the [http://api.kde.org/4.x-api/kdelibs-apidocs/kdeui/html/kmainwindow_8h.html#88ce427e39f425eefa5a94d746eb2bed kRestoreMainWindows<>()] template functions for up to three template arguments.

@@ Line 71: / Line 71: @@
 * [http://api.kde.org/4.x-api/kdelibs-apidocs/kdeui/html/classKMainWindow.html#c8d0d64ed5b309ba1da410423120d0a6 readProperties()]: To read the additional data again on next login, reimplement this function.
-Furthermore, the function [http://api.kde.org/4.x-api/kdelibs-apidocs/kdeui/html/classKMainWindow.html#f8c5708414be62f259114b0453ef8432 queryClose()] could be interesting for you. This function is called ''always'' before the window is closed, either by the user or indirectly by the session manager. Typically, here you can warn the user that the application or some windows have unsaved data on close or logout (for example: show a dialog with the buttons "Save changes" and "Discard changes"). However, for session management it isn't nice to request a user interaction before closing, so you better avoid this. Note that it is not determined if [http://api.kde.org/4.x-api/kdelibs-apidocs/kdeui/html/classKMainWindow.html#4c7a6c395eec0bb245cd9ad6c884f897 saveProperties()] is called before or after [http://api.kde.org/4.x-api/kdelibs-apidocs/kdeui/html/classKMainWindow.html#f8c5708414be62f259114b0453ef8432 queryClose()]!
+Furthermore, the function [http://api.kde.org/4.x-api/kdelibs-apidocs/kdeui/html/classKMainWindow.html#f8c5708414be62f259114b0453ef8432 queryClose()] could be interesting for you. This function is called ''always'' before the window is closed, either by the user or indirectly by the session manager. ''(Note that this is not the case for a call of KApplication::quit() because this function will exit the event loop without causing a close event for the main windows. It will even not destroy them.)'' Typically, here you can warn the user that the application or some windows have unsaved data on close or logout (for example: show a dialog with the buttons "Save changes" and "Discard changes"). However, for session management it isn't nice to request a user interaction before closing, so you better avoid this. Note that it is not determined if [http://api.kde.org/4.x-api/kdelibs-apidocs/kdeui/html/classKMainWindow.html#4c7a6c395eec0bb245cd9ad6c884f897 saveProperties()] is called before or after [http://api.kde.org/4.x-api/kdelibs-apidocs/kdeui/html/classKMainWindow.html#f8c5708414be62f259114b0453ef8432 queryClose()]!
 ''To save your application-wide properties (data that is only needed once per application, and not for each main window instance) reimplement [http://api.kde.org/4.x-api/kdelibs-apidocs/kdeui/html/classKMainWindow.html#cf811d77a3acdcf2b61f8826429615a7 saveGlobalProperties()] and it's counterpart [http://api.kde.org/4.x-api/kdelibs-apidocs/kdeui/html/classKMainWindow.html#2d4da4f305f00e8a5c94f5b978334231 readGlobalProperties].  Normally, you don't need these functions.''

@@ Line 3: / Line 3: @@
 {{TutorialBrowser|
-series=TBD|
+series=Basics|
 name=Session Management|
-pre=[[Development/Tutorials/pre|TBD]]|
+pre=[[Development/Tutorials/Creating_Libraries|Creating Libraries]]|
-next=[[Development/Tutorials/next|TBD]]|
+next=|
 reading=[http://doc.trolltech.com/4.4/session.html Session Management in the Qt documentation]; [http://api.kde.org/4.x-api/kdelibs-apidocs/kdeui/html/classKMainWindow.html KMainWindow]; [http://api.kde.org/4.x-api/kdelibs-apidocs/kdeui/html/classKApplication.html KApplication]

@@ Line 65: / Line 65: @@
 ===Reimplement some virtual functions of KMainWindow===
-[http://api.kde.org/4.x-api/kdelibs-apidocs/kdeui/html/classKMainWindow.html KMainWindow] will save its position, geometry and positions of toolbars and menubar on logout.
+[http://api.kde.org/4.x-api/kdelibs-apidocs/kdeui/html/classKMainWindow.html KMainWindow] will automatically save its position, geometry and positions of toolbars and menubar on logout - and restore it on the next startup.
-* To warn the user that the application or some windows have unsaved data on close or logout (for example: show a dialog with the buttons "Save changes" and "Discard changes"), reimplement [http://api.kde.org/4.x-api/kdelibs-apidocs/kdeui/html/classKMainWindow.html#f8c5708414be62f259114b0453ef8432 queryClose()].
-* To save additional data, reimplement [http://api.kde.org/4.x-api/kdelibs-apidocs/kdeui/html/classKMainWindow.html#4c7a6c395eec0bb245cd9ad6c884f897 saveProperties()]. (For a text editor, that would be the loaded files, for example.) Note that no user interaction is allowed in this function! For example, you may not display any dialog!
-* To read the additional data again on next login, reimplement [http://api.kde.org/4.x-api/kdelibs-apidocs/kdeui/html/classKMainWindow.html#c8d0d64ed5b309ba1da410423120d0a6 readProperties()].
-These functions are called automatically by [http://api.kde.org/4.x-api/kdelibs-apidocs/kdeui/html/classKMainWindow.html KMainWindow] respectively by the session manager. Note that it is not determined if [http://api.kde.org/4.x-api/kdelibs-apidocs/kdeui/html/classKMainWindow.html#4c7a6c395eec0bb245cd9ad6c884f897 saveProperties()] is called before or after [http://api.kde.org/4.x-api/kdelibs-apidocs/kdeui/html/classKMainWindow.html#f8c5708414be62f259114b0453ef8432 queryClose()]! Please read documentation of the respective functions before reimplementing them.
-To save your application-wide properties (data that is only needed once per application, and not for each main window) reimplement [http://api.kde.org/4.x-api/kdelibs-apidocs/kdeui/html/classKMainWindow.html#cf811d77a3acdcf2b61f8826429615a7 saveGlobalProperties()] and it's counterpart [http://api.kde.org/4.x-api/kdelibs-apidocs/kdeui/html/classKMainWindow.html#2d4da4f305f00e8a5c94f5b978334231 readGlobalProperties].  Normally, you don't need these functions.
+For every other data that your application needs to restore a session, you have to write the code for saving and restoring yourself. However, [http://api.kde.org/4.x-api/kdelibs-apidocs/kdeui/html/classKMainWindow.html KMainWindow] makes this task easy. You can just re-implement the following functions:
 ===Add session management support to your main() function===
-While [http://api.kde.org/4.x-api/kdelibs-apidocs/kdeui/html/classKMainWindow.html#4c7a6c395eec0bb245cd9ad6c884f897 KMainWindow::saveProperties()] and [http://api.kde.org/4.x-api/kdelibs-apidocs/kdeui/html/classKMainWindow.html#f8c5708414be62f259114b0453ef8432 KMainWindow::queryClose()] will be called automatically, [http://api.kde.org/4.x-api/kdelibs-apidocs/kdeui/html/classKMainWindow.html#c8d0d64ed5b309ba1da410423120d0a6 KMainWindow::readProperties()] will not. You have to add some code to your main() function to implement session restoring.
+While [http://api.kde.org/4.x-api/kdelibs-apidocs/kdeui/html/classKMainWindow.html#4c7a6c395eec0bb245cd9ad6c884f897 KMainWindow::saveProperties()] (and also [http://api.kde.org/4.x-api/kdelibs-apidocs/kdeui/html/classKMainWindow.html#f8c5708414be62f259114b0453ef8432 KMainWindow::queryClose()]) will be called automatically, [http://api.kde.org/4.x-api/kdelibs-apidocs/kdeui/html/classKMainWindow.html#c8d0d64ed5b309ba1da410423120d0a6 KMainWindow::readProperties()] will not. You have to add some code to your main() function to implement session restoring.
 Imagine you have an
@@ Line 82: / Line 84: @@
 [http://api.kde.org/4.x-api/kdelibs-apidocs/kdeui/html/classKXmlGuiWindow.html KXmlGuiWindow], which inherits from
 [http://api.kde.org/4.x-api/kdelibs-apidocs/kdeui/html/classKMainWindow.html KMainWindow]). In your main() function, you would then create/restore the
-application windows with something like:
+application windows with something like this:
 <code cppqt>

@@ Line 44: / Line 44: @@
 hide all the ugly details from the programmer. Basically, a
 [http://api.kde.org/4.x-api/kdelibs-apidocs/kdeui/html/classKApplication.html KApplication] manages a
-[http://api.kde.org/4.x-api/kdelibs-apidocs/kdecore/html/classKConfig.html KConfig] configuration object
+[http://api.kde.org/4.x-api/kdelibs-apidocs/kdecore/html/classKConfig.html KConfig] configuration object (available trought
-[http://api.kde.org/4.x-api/kdelibs-apidocs/kdeui/html/classKApplication.html#8f88369c240d6d90a04d29b2761989d9 sessionConfig()]
+[http://api.kde.org/4.x-api/kdelibs-apidocs/kdeui/html/classKApplication.html#8f88369c240d6d90a04d29b2761989d9 KApplication::sessionConfig()])
 for you, that your application can utilize to store session specific data.

← Older revision		Revision as of 07:40, 6 April 2009
Line 1:		Line 1:
	{{Template:I18n/Language Navigation Bar\|Development/Tutorials/Session Management}}		{{Template:I18n/Language Navigation Bar\|Development/Tutorials/Session Management}}
		+
		+	{{TutorialBrowser\|
		+
		+	series=TBD\|
		+
		+	name=Session Management\|
		+
		+	pre=[[Development/Tutorials/pre\|TBD]]\|
		+
		+	next=[[Development/Tutorials/next\|TBD]]\|
		+
		+	reading=[http://api.kde.org/4.x-api/kdelibs-apidocs/kdeui/html/classKMainWindow.html KMainWindow]; [http://api.kde.org/4.x-api/kdelibs-apidocs/kdeui/html/classKApplication.html KApplication]; [http://doc.trolltech.com/4.4/session.html Session Management in the Qt documentation]
		+	}}

	==About KDE and X11 session management==		==About KDE and X11 session management==