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Main Windows in Java Drawer Code 128A in Java Main Windows




How to generate, print barcode using .NET, Java sdk library control with example project source code free download:
6. Main Windows use j2se code 128b generating toget code 128a on java QR Code Safty Figure 6.6 The Edit toolbar The pattern fo r adding widgets to a toolbar is always the same: We create the widget, set it up, connect it to something to handle user interaction, and add it to the toolbar. We have made the spinbox an instance variable because we will need to access it outside the main window s initializer. The addWidget() call passes ownership of the spinbox to the toolbar.

We have now fully populated the menus and toolbars with actions. Although every action was added to the menus, some were not added to the toolbars. This is quite conventional; usually only the most frequently used actions are added to toolbars.

Earlier we saw the following line of code:. self.imageLabe barcode 128 for Java l.setContextMenuPolicy(Qt.

ActionsContextMenu). This tells PyQ t that if actions are added to the imageLabel widget, they are to be used for a context menu, such as the one shown in Figure 6.7..

self.addAction jsp barcode standards 128 s(self.imageLabel, (editInvertAction, editSwapRedAndBlueAction, editUnMirrorAction, editMirrorVerticalAction, editMirrorHorizontalAction)).

We can reuse o ur addActions() method to add actions to the label widget, providing we don t pass Nones since QWidget does not have an addSeparator() method. Setting the policy and adding actions to a widget are all that is necessary to get a context menu for that widget..

Figure 6.7 The Image Label s context menu The QWidget cl ass has an addAction() method that is inherited by the QMenu, QMenuBar, and QToolBar classes. This is why we can add actions to any of these classes. Although the QWidget class does not have an addSeparator() method, one is provided for convenience in the QMenu, QMenuBar, and QToolBar classes.

If we want to add a separator to a context menu, we must do so by adding a separator action. For example:. Creating a Main Window separator = QA ction(self) separator.setSeparator(True) self.addActions(editToolbar, (editInvertAction, editSwapRedAndBlueAction, separator, editUnMirrorAction, editMirrorVerticalAction, editMirrorHorizontalAction)).

If we need mor barcode 128a for Java e sophisticated context menu handling for example, where the menu s actions vary depending on the application s state, we can reimplement the relevant widget s contextMenuEvent() event-handling method. Event handling is covered in 10. When we create a new image or load an existing image, we want the user interface to revert to its original state.

In particular, we want the edit invert and edit swap red and green actions to be off , and the mirror action to be edit unmirrored .. self.resetable Actions = ((editInvertAction, False), (editSwapRedAndBlueAction, False), (editUnMirrorAction, True)). contextMenuEvent(). 307. We have create servlet code 128 barcode d an instance variable holding a tuple of pairs, with each pair holding an action and the checked state it should have when a new image is created or loaded. We will see resetableActions in use when we review the fileNew() and loadFile() slots. In the Image Changer application, all of the actions are enabled all of the time.

This is ne, since we always check for a null image before performing any action, but it has the disadvantage that, for example, le save will be enabled if there is no image or if there is an unchanged image, and similarly, the edit actions will be enabled even if there is no image. The solution is to enable or disable actions depending on the application s state, as the sidebar in 13 shows..

Enabling and Disabling Actions sidebar 385. Restoring and Saving the Main Window s State Now that the m jdk Code128 ain window s user interface has been fully set up, we are almost ready to nish the initializer method, but before we do we will restore the application s settings from the previous run (or use default settings if this is the very rst time the application has been run). Before we can look at application settings, though, we must make a quick detour and look at the creation of the application object and how the main window itself is created. The very last executable statement in the imagechanger.

pyw le is the bare function call:. main(). As usual, we h jboss code 128a ave chosen to use a conventional name for the rst function we execute. Here is its code:. def main(): ap p = QApplication(sys.argv) app.setOrganizationName("Qtrac Ltd.

") app.setOrganizationDomain("qtrac.eu") app.

setApplicationName("Image Changer") app.setWindowIcon(QIcon(":/icon.png")) form = MainWindow() form.

show() app.exec_().
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