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< td align = "right" valign = "center" > < img src = "logo32.png" align = "right" width = "64" height = "32" border = "0" > < / td > < / tr > < / table > < h1 align = center > Using TQt Standard Dialogs< / h1 >
[ < a href = "motif-walkthrough-2.html" > Previous: Preparing to Migrate the User Interface< / a > ]
[ < a href = "motif-walkthrough.html" > Home< / a > ]
[ < a href = "motif-walkthrough-4.html" > Next: Using Custom TQDialogs< / a > ]
< p > We start by using two of the < a href = "dialogs.html" > TQt Standard
Dialogs< / a > : < a href = "tqfiledialog.html" > TQFileDialog< / a > and < a href = "tqmessagebox.html" > TQMessageBox< / a > . Both of these classes
provide useful static convenience functions.
< p > < center > < table cellpadding = "4" cellspacing = "2" border = "0" >
< tr bgcolor = "#f0f0f0" > < td valign = "top" > TQFileDialog::getOpenFileName() < td valign = "top" > replacement for the < em > Open< / em > dialog
< tr bgcolor = "#d0d0d0" > < td valign = "top" > TQFileDialog::getSaveFileName() < td valign = "top" > replacement for the < em > Save As< / em > dialog
< tr bgcolor = "#f0f0f0" > < td valign = "top" > TQMessageBox::information() < td valign = "top" > replacement for < em > Page Delete< / em > dialog
< tr bgcolor = "#d0d0d0" > < td valign = "top" > TQMessageBox::warning() < td valign = "top" > replacement for < em > IO Error< / em > dialog.
< / table > < / center >
< p > Each of these functions takes a < em > TQWidget *parent< / em > argument. If we
pass zero as the < em > parent< / em > argument, then we will have dialogs that
are centered on the screen, instead of being centered over our main
window. We can have < a href = "tqmotifwidget.html" > TQMotifWidget< / a > create our < tt > XmMainWindow< / tt > , and we
can then use this class as the parent for both < a href = "motif-extension.html#Motif" > Motif< / a > dialogs and TQt
dialogs.
< p > We need to include the appropriate headers for TQMotifWidget and
< a href = "tqfiledialog.html" > TQFileDialog< / a > in < tt > todo.cpp< / tt > .
< p >
< pre > < / pre >
< p > Next, we make a few modifications to how the application is
initialized. We could initialize Xt/Motif and create the < tt > XtAppContext< / tt > ourselves, but < a href = "tqmotif.html" > TQMotif< / a > can do this for us.
We also let < a href = "ntqapplication.html" > TQApplication< / a > open the connection to the X server. Next,
we create a TQMotifWidget, passing < tt > xmMainWindowWidgetClass< / tt > as the < em > widgetclass< / em > argument. We can now use the < a href = "tqmotifwidget.html#motifWidget" > TQMotifWidget::motifWidget< / a > ()
function to access the Motif widget. The shell widget is created
automatically by TQMotifWidget. We use < tt > XtParent()< / tt > to access it.
The top-level window is now a TQMotifWidget, which means we can use it
as the parent for the TQt Standard Dialogs.
< p > < pre > < / pre >
< p > < h2 > Replacing the < em > Open< / em > and < em > Save As< / em > Dialogs
< / h2 >
< a name = "1" > < / a > < p > First, we completely remove all use of the existing Motif file
selection dialog. We remove the < tt > Xm/FileSB.h< / tt > include, the global < tt > file_dialog< / tt > variable, and the code to create the dialog. We also
remove the < tt > PresentFDialog()< / tt > callback function. None of this code
is needed to use < a href = "tqfiledialog.html" > TQFileDialog< / a > .
< p > After removing the < tt > PresentFDialog()< / tt > callback function, we need to
make < em > Open< / em > and < em > Save As< / em > popup-menu callbacks call the < tt > Open()< / tt >
and < tt > Save()< / tt > functions.
< p > First we must change the declaration of these two functions.
< p >
< p > < pre > < / pre >
< p > We also change the arguments to the callbacks. We pass the top-level
< a href = "tqmotifwidget.html" > TQMotifWidget< / a > as the < tt > client_data< / tt > to these functions, since we will
be using it as the parent for the TQFileDialog.
< p > < pre > < / pre >
< p > < pre >
...
< / pre >
< p > < pre > < / pre >
< p > Next, we modify the < tt > Save()< / tt > function to use
< a href = "tqfiledialog.html#getSaveFileName" > TQFileDialog::getSaveFileName< / a > ().
< p > < pre > < / pre >
< p > ... and the < tt > Open()< / tt > function to use < a href = "tqfiledialog.html#getOpenFileName" > TQFileDialog::getOpenFileName< / a > ().
< p > < pre > < / pre >
< p > After we build the project, the application runs and operates as
expected. The difference is that the < em > Open< / em > and < em > Save As< / em > dialogs
now use < a href = "tqfiledialog.html" > TQFileDialog< / a > .
< p > < h2 > Replacing the < em > Page Delete< / em > and < em > IO Error< / em > Dialogs
< / h2 >
< a name = "2" > < / a > < p > The < em > Page Delete< / em > dialog is created and used in < tt > actions.c< / tt > . We
need to migrate this file to C++. We rename it to < tt > actions.cpp< / tt > ,
modify the project file and regenerate the < tt > Makefile< / tt > .
< p > The changes required to make < tt > actions.cpp< / tt > compile are minimal. We
need to wrap more C header files and global variables in an < tt > extern "C"< / tt > block.
< p >
< p > < pre > < / pre >
< p > We need to forward declare the < tt > NewPage()< / tt > , < tt > DeletePage()< / tt > , < tt > EditPage()< / tt > and < tt > SaveIt()< / tt > functions so that the compiler generates
the correct symbols for these functions.
< p > < pre > < / pre >
< p > We need to fix a single invalid pointer cast.
< p > < pre > < / pre >
< p > And we need to change the variable named < em > new< / em > to < em > newstr< / em > in the < tt > Trim()< / tt > function.
< p > We can now change the < tt > DeletePage()< / tt > function to use
< a href = "tqmessagebox.html#information" > TQMessageBox::information< / a > ().
< p > First, we need to make sure we include the proper header for
< a href = "tqmessagebox.html" > TQMessageBox< / a > .
< p >
< pre > < / pre >
< p > The code for < tt > DeletePage()< / tt > looks like this:
< p > < pre > < / pre >
< p > At this point in the code, the page should be deleted. The code to do
this is in the < tt > DoDeletePage()< / tt > function. We move the contents of < tt > DoDeletePage()< / tt > to this point and remove the < tt > DoDeletePage()< / tt > function
completely.
< p > Next, we change < tt > todo.cpp< / tt > to pass the top-level < a href = "tqmotifwidget.html" > TQMotifWidget< / a > as the
< tt > client_data< / tt > tot he < tt > DeletePage()< / tt > function.
< p >
< p > < pre > < / pre >
< p > The < em > IO Error< / em > dialog is created and used in < tt > io.c< / tt > . We need to
migrate this file to C++. We rename it to < tt > io.cpp< / tt > , modify the
project file and regenerate the < tt > Makefile< / tt > .
< p > The changes required to make < tt > io.cpp< / tt > compile are minimal. We need
to wrap more C header files and global variables in an < tt > extern "C"< / tt >
block.
< p >
< p > < pre > < / pre >
< p > We need to forward declare the < tt > ReadDB()< / tt > and < tt > SaveDB()< / tt > functions
so that the compiler generates the correct symbols for these
functions.
< p > < pre > < / pre >
< p > The < tt > ParseNewLines()< / tt > function needs to be converted to proper C++.
< p > < pre > < / pre >
< p > The < tt > PrintWithNewLines()< / tt > function also needs to be converted to proper
C++.
< p > < pre > < / pre >
< p > We can now change the < tt > ReadDB()< / tt > and < tt > SaveDB()< / tt > functions to use
< a href = "tqmessagebox.html#warning" > TQMessageBox::warning< / a > ().
< p > First, we need to make sure we include the proper header for < a href = "tqmessagebox.html" > TQMessageBox< / a > .
< p >
< pre > < / pre >
< p > The code for < tt > ReadDB()< / tt > looks like this:
< p > < pre > < / pre > < pre >
...
< / pre >
< p > The code for < tt > SaveDB()< / tt > looks like this:
< p > < pre > < / pre > < pre >
...
< / pre >
< p > After we build the project, the application runs and operates as
expected. The difference is that the < em > Page Delete< / em > and < em > IO Error< / em > dialogs now use TQMessageBox.
< p > [ < a href = "motif-walkthrough-2.html" > Previous: Preparing to Migrate the User Interface< / a > ]
[ < a href = "motif-walkthrough.html" > Home< / a > ]
[ < a href = "motif-walkthrough-4.html" > Next: Using Custom TQDialogs< / a > ]
< p >
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