From bd0f3345a938b35ce6a12f6150373b0955b8dd12 Mon Sep 17 00:00:00 2001 From: Timothy Pearson Date: Sun, 10 Jul 2011 15:24:15 -0500 Subject: Add Qt3 development HEAD version --- doc/html/motif-walkthrough-3.html | 178 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 178 insertions(+) create mode 100644 doc/html/motif-walkthrough-3.html (limited to 'doc/html/motif-walkthrough-3.html') diff --git a/doc/html/motif-walkthrough-3.html b/doc/html/motif-walkthrough-3.html new file mode 100644 index 0000000..2d250eb --- /dev/null +++ b/doc/html/motif-walkthrough-3.html @@ -0,0 +1,178 @@ + + + + + +Using Qt Standard Dialogs + + + + + + + +

Using Qt Standard Dialogs

+ + + +[ Previous: Preparing to Migrate the User Interface ] +[ Home ] +[ Next: Using Custom QDialogs ] +

We start by using two of the Qt Standard +Dialogs: QFileDialog and QMessageBox. Both of these classes +provide useful static convenience functions. +

QFileDialog::getOpenFileName()	replacement for the Open dialog +
QFileDialog::getSaveFileName()	replacement for the Save As dialog +
QMessageBox::information()	replacement for Page Delete dialog +
QMessageBox::warning()	replacement for IO Error dialog. +

Each of these functions takes a QWidget *parent argument. If we +pass zero as the parent argument, then we will have dialogs that +are centered on the screen, instead of being centered over our main +window. We can have QMotifWidget create our XmMainWindow, and we +can then use this class as the parent for both Motif dialogs and Qt +dialogs. +

We need to include the appropriate headers for QMotifWidget and +QFileDialog in todo.cpp. +

+ +

Next, we make a few modifications to how the application is +initialized. We could initialize Xt/Motif and create the XtAppContext ourselves, but QMotif can do this for us. +We also let QApplication open the connection to the X server. Next, +we create a QMotifWidget, passing xmMainWindowWidgetClass as the widgetclass argument. We can now use the QMotifWidget::motifWidget() +function to access the Motif widget. The shell widget is created +automatically by QMotifWidget. We use XtParent() to access it. +The top-level window is now a QMotifWidget, which means we can use it +as the parent for the Qt Standard Dialogs. +

Replacing the Open and Save As Dialogs +

First, we completely remove all use of the existing Motif file +selection dialog. We remove the Xm/FileSB.h include, the global file_dialog variable, and the code to create the dialog. We also +remove the PresentFDialog() callback function. None of this code +is needed to use QFileDialog. +

After removing the PresentFDialog() callback function, we need to +make Open and Save As popup-menu callbacks call the Open() +and Save() functions. +

First we must change the declaration of these two functions. +

+ +

We also change the arguments to the callbacks. We pass the top-level +QMotifWidget as the client_data to these functions, since we will +be using it as the parent for the QFileDialog. +

+    ...
+

+ +

Next, we modify the Save() function to use +QFileDialog::getSaveFileName(). +

... and the Open() function to use QFileDialog::getOpenFileName(). +

After we build the project, the application runs and operates as +expected. The difference is that the Open and Save As dialogs +now use QFileDialog. +

Replacing the Page Delete and IO Error Dialogs +

The Page Delete dialog is created and used in actions.c. We +need to migrate this file to C++. We rename it to actions.cpp, +modify the project file and regenerate the Makefile. +

The changes required to make actions.cpp compile are minimal. We +need to wrap more C header files and global variables in an extern "C" block. +

+ +

We need to forward declare the NewPage(), DeletePage(), EditPage() and SaveIt() functions so that the compiler generates +the correct symbols for these functions. +

We need to fix a single invalid pointer cast. +

And we need to change the variable named new to newstr in the Trim() function. +

We can now change the DeletePage() function to use +QMessageBox::information(). +

First, we need to make sure we include the proper header for +QMessageBox. +

+ +

The code for DeletePage() looks like this: +

At this point in the code, the page should be deleted. The code to do +this is in the DoDeletePage() function. We move the contents of DoDeletePage() to this point and remove the DoDeletePage() function +completely. +

Next, we change todo.cpp to pass the top-level QMotifWidget as the +client_data tot he DeletePage() function. +

+ +

The IO Error dialog is created and used in io.c. We need to +migrate this file to C++. We rename it to io.cpp, modify the +project file and regenerate the Makefile. +

The changes required to make io.cpp compile are minimal. We need +to wrap more C header files and global variables in an extern "C" +block. +

+ +

We need to forward declare the ReadDB() and SaveDB() functions +so that the compiler generates the correct symbols for these +functions. +

The ParseNewLines() function needs to be converted to proper C++. +

The PrintWithNewLines() function also needs to be converted to proper +C++. +

We can now change the ReadDB() and SaveDB() functions to use +QMessageBox::warning(). +

First, we need to make sure we include the proper header for QMessageBox. +

+ +

The code for ReadDB() looks like this: +

+    ...
+

+ +

The code for SaveDB() looks like this: +

+    ...
+

+ +

After we build the project, the application runs and operates as +expected. The difference is that the Page Delete and IO Error dialogs now use QMessageBox. +

[ Previous: Preparing to Migrate the User Interface ] +[ Home ] +[ Next: Using Custom QDialogs ] +

+ +

Trademarks +

Qt 3.3.8

+ -- cgit v1.2.1