qwidget.3qt

tmark1.11:用于生成QT/EMBEDDED应用工程的Markfile文件

\fBWarning:\fR Grabbing the mouse might lock the terminal.
.PP
It is almost never necessary to grab the mouse when using Qt since Qt grabs and releases it sensibly. In particular, Qt grabs the mouse when a button is pressed and keeps it until the last button is released.
.PP
See also: releaseMouse(), grabKeyboard() and releaseKeyboard().
.SH "void QWidget::grabMouse ( const QCursor & cursor )"
Grabs the mouse input and changes the cursor shape.
.PP
The cursor will assume shape \fIcursor\fR (for as long as the mouse focus is grabbed) and this widget will be the only one to receive mouse events until releaseMouse() is called().
.PP
\fBWarning:\fR Grabbing the mouse might lock the terminal.
.PP
See also: releaseMouse(), grabKeyboard(), releaseKeyboard() and setCursor().
.PP
Examples:
.(l
qmag/qmag.cpp
.)l
.SH "bool QWidget::hasFocus () const"
Returns TRUE if this widget (or its focus proxy) has the keyboard input focus, otherwise FALSE.
.PP
Equivalent to \fCqApp->focusWidget() == this\fR.
.PP
See also: setFocus(), clearFocus(), setFocusPolicy() and QApplication::focusWidget().
.SH "bool QWidget::hasMouseTracking () const"
Returns TRUE if mouse tracking is enabled for this widget, or FALSE if mouse tracking is disabled.
.PP
See also: setMouseTracking().
.SH "int QWidget::height () const"
Returns the height of the widget, excluding the window frame.
.PP
See also: geometry(), width() and size().
.PP
Examples:
.(l
grapher/grapher.cpp xform/xform.cpp drawdemo/drawdemo.cpp qmag/qmag.cpp
.)l
.SH "int QWidget::heightForWidth ( int w ) const \fC[virtual]\fR"
Returns the preferred height for this widget, given the width \fIw.\fR The default implementation returns 0, indicating that the preferred height does not depend on the width.
.PP
\fBWarning:\fR Does not look at the widget's layout.
.PP
Reimplemented in QMenuBar, QLabel and QTextView.
.SH "void QWidget::hide () \fC[virtual slot]\fR"
Hides the widget.
.PP
You almost never have to reimplement this function. If you need to do something after a widget is hidden, use \\link hideEvent() instead.
.PP
See also: \\hideEvent(), show(), showMinimized(), isVisible() and close().
.PP
Examples:
.(l
xform/xform.cpp popup/popup.cpp progress/progress.cpp scrollview/scrollview.cpp
.)l
.PP
Reimplemented in QPopupMenu and QMenuBar.
.SH "void QWidget::hideEvent ( QHideEvent * ) \fC[virtual protected]\fR"
This event handler can be reimplemented in a subclass to receive widget hide events.
.PP
Hide events are sent to widgets right after they have been hidden.
.PP
See also: event() and QHideEvent.
.SH "const QPixmap * QWidget::icon () const"
Returns the widget icon pixmap, or null if no icon has been set.
.PP
See also: setIcon(), iconText() and caption().
.SH "QString QWidget::iconText () const"
Returns the widget icon text, or a null string if no icon text has been set.
.PP
See also: setIconText(), icon() and caption().
.SH "bool QWidget::isActiveWindow () const"
Returns TRUE if the top-level widget containing this widget is the active window.
.PP
See also: setActiveWindow() and topLevelWidget().
.SH "bool QWidget::isDesktop () const"
Returns TRUE if the widget is a desktop widget, otherwise FALSE.
.PP
A desktop widget is also a top-level widget.
.PP
See also: isTopLevel() and QApplication::desktop().
.SH "bool QWidget::isEnabled () const"
Returns TRUE if the widget is enabled, or FALSE if it is disabled.
.PP
See also: setEnabled().
.SH "bool QWidget::isEnabledTo ( QWidget * ancestor ) const"
Returns TRUE if this widget and every parent up to but excluding \fIancestor\fR is enabled, otherwise returns FALSE.
.PP
See also: setEnabled() and isEnabled().
.SH "bool QWidget::isEnabledToTLW () const"
Returns TRUE if this widget and every parent up to the top level widget is enabled, otherwise returns FALSE.
.PP
This is equivalent to isEnabledTo(0).
.PP
See also: setEnabled() and isEnabled().
.SH "bool QWidget::isFocusEnabled () const"
Returns TRUE if the widget accepts keyboard focus, or FALSE if it does not.
.PP
Keyboard focus is initially disabled (i.e. focusPolicy() == \fCQWidget::NoFocus).\fR
.PP
You must enable keyboard focus for a widget if it processes keyboard events. This is normally done from the widget's constructor. For instance, the QLineEdit constructor calls setFocusPolicy(\fCQWidget::StrongFocus).\fR
.PP
See also: setFocusPolicy(), focusInEvent(), focusOutEvent(), keyPressEvent(), keyReleaseEvent() and isEnabled().
.SH "bool QWidget::isMinimized () const"
Returns TRUE if this widget is a top-level widget that is minimized (iconified), or else FALSE.
.PP
See also: showMinimized(), isVisible(), show(), hide() and showNormal().
.SH "bool QWidget::isModal () const"
Returns TRUE if the widget is a modal widget, otherwise FALSE.
.PP
A modal widget is also a top-level widget.
.PP
See also: isTopLevel() and QDialog.
.SH "bool QWidget::isPopup () const"
Returns TRUE if the widget is a popup widget, otherwise FALSE.
.PP
A popup widget is created by specifying the widget flag \fCWType_Popup\fR to the widget constructor.
.PP
A popup widget is also a top-level widget.
.PP
See also: isTopLevel().
.SH "bool QWidget::isTopLevel () const"
Returns TRUE if the widget is a top-level widget, otherwise FALSE.
.PP
A top-level widget is a widget which usually has a frame and a caption (title bar). Popup and desktop widgets are also top-level widgets.
.PP
A top-level widgets can have a parent widget. It will then be grouped with its parent: deleted when the parent is deleted, minimized when the parent is minimized etc. If supported by the window manager, it will also have a common taskbar entry with its parent.
.PP
QDialog and QMainWindow widgets are by default top-level, even if a parent widget is specified in the constructor. This behavior is specified by the \fCWType_TopLevel\fR widget flag.
.PP
Child widgets are the opposite of top-level widgets.
.PP
See also: topLevelWidget(), isModal(), isPopup(), isDesktop() and parentWidget().
.SH "bool QWidget::isUpdatesEnabled () const"
Returns TRUE if updates are enabled, otherwise FALSE.
.PP
See also: setUpdatesEnabled().
.SH "bool QWidget::isVisible () const"
Returns TRUE if the widget itself is set to visible status, or else FALSE. Calling show() sets the widget to visible status; calling hide() sets it to hidden status. Iconified top-level widgets also have hidden status, as well as having isMinimized() return TRUE.
.PP
If a widget is set to visible status, but its parent widget is set to hidden status, this function returns TRUE. isVisibleToTLW() looks at the visibility status of the parent widgets up to the top level widget.
.PP
This function returns TRUE if the widget currently is obscured by other windows on the screen, but would be visible if moved.
.PP
See also: show(), hide(), isVisibleToTLW() and isMinimized().
.SH "bool QWidget::isVisibleTo ( QWidget * ancestor ) const"
Returns TRUE if this widget and every parent up to but excluding \fIancestor\fR is visible, otherwise returns FALSE.
.PP
This function returns TRUE if the widget it is obscured by other windows on the screen, but would be visible if moved.
.PP
See also: show(), hide() and isVisible().
.SH "bool QWidget::isVisibleToTLW () const"
Returns TRUE if this widget and every parent up to the top level widget is visible, otherwise returns FALSE.
.PP
This function returns TRUE if the widget it is obscured by other windows on the screen, but would be visible if moved.
.PP
This is equivalent to isVisibleTo(0).
.PP
See also: show(), hide() and isVisible().
.SH "void QWidget::keyPressEvent ( QKeyEvent * e ) \fC[virtual protected]\fR"
This event handler can be reimplemented in a subclass to receive key press events for the widget.
.PP
A widget must accept focus initially and have focus in order to receive a key press event.
.PP
If you reimplement this handler, it is very important that you ignore() the press if you do not understand it, so that the widget's parent can interpret it.
.PP
The default implementation closes popup widgets if you hit escape. Otherwise the event is ignored.
.PP
As a special case to support applications not utilizing focus, Top-level widgets that have NoFocus policy will receive keyboard events.
.PP
See also: keyReleaseEvent(), QKeyEvent::ignore(), setFocusPolicy(), focusInEvent(), focusOutEvent(), event() and QKeyEvent.
.PP
Reimplemented in QComboBox, QButton, QDial, QTextBrowser, QSlider, QDialog, QMultiLineEdit, QLineEdit, QTextView, QMessageBox, QMenuBar, QListBox, QListView, QPopupMenu, QScrollBar, QFileDialog and QTabBar.
.SH "void QWidget::keyReleaseEvent ( QKeyEvent * e ) \fC[virtual protected]\fR"
This event handler can be reimplemented in a subclass to receive key release events for the widget.
.PP
A widget must accept focus initially and have focus in order to receive a key release event.
.PP
If you reimplement this handler, it is very important that you ignore() the release if you do not understand it, so that the widget's parent can interpret it.
.PP
The default implementation ignores the event.
.PP
See also: keyPressEvent(), QKeyEvent::ignore(), setFocusPolicy(), focusInEvent(), focusOutEvent(), event() and QKeyEvent.
.SH "QWidget * QWidget::keyboardGrabber () \fC[static]\fR"
Returns a pointer to the widget that is currently grabbing the keyboard input.
.PP
If no widget in this application is currently grabbing the keyboard, 0 is returned.
.PP
See also: grabMouse() and mouseGrabber().
.SH "QLayout* QWidget::layout () const"
Returns a pointer to the layout engine that manages the geometry of this widget's children.
.PP
If the widget does not have a layout, layout() returns a null pointer.
.PP
See also: sizePolicy().
.SH "void QWidget::leaveEvent ( QEvent * ) \fC[virtual protected]\fR"
This event handler can be reimplemented in a subclass to receive widget leave events.
.PP
A leave event is sent to the widget when the mouse cursor leaves the widget.
.PP
See also: enterEvent(), mouseMoveEvent() and event().
.PP
Reimplemented in QToolButton, QMenuBar, QXtWidget, QMultiLineEdit and QLineEdit.
.SH "void QWidget::lower () \fC[slot]\fR"
Lowers the widget to the bottom of the parent widget's stack.
.PP
If there are siblings of this widget that overlap it on the screen, this widget will be obscured by its siblings afterwards.
.PP
See also: raise().
.SH "QPoint QWidget::mapFromGlobal ( const QPoint & pos ) const"
Translates the global screen coordinate \fIpos\fR to widget coordinates.
.PP
See also: mapToGlobal().
.SH "QPoint QWidget::mapFromParent ( const QPoint & p ) const"
Translates the parent widget coordinate \fIpos\fR to widget coordinates.
.PP
Same as mapFromGlobal() if the widget has no parent.
.PP
See also: mapToParent().
.SH "QPoint QWidget::mapToGlobal ( const QPoint & pos ) const"
Translates the widget coordinate \fIpos\fR to global screen coordinates. For example,
.PP
.nf
.br
 mapToGlobal(QPoint(0,0))
.fi
would give the global coordinates of the top-left pixel of the widget.
.PP
See also: mapFromGlobal().
.PP
Examples:
.(l
popup/popup.cpp
.)l
.SH "QPoint QWidget::mapToParent ( const QPoint & p ) const"
Translates the widget coordinate \fIpos\fR to a coordinate in the parent widget.
.PP
Same as mapToGlobal() if the widget has no parent.
.PP
See also: mapFromParent().
.SH "int QWidget::maximumHeight () const"
Returns the widget's maximum height.
.PP
See also: maximumSize() and maximumWidth().
.SH "QSize QWidget::maximumSize () const"
Returns the maximum widget size.
.PP
The widget cannot be resized to a larger size than the maximum widget size.
.PP
See also: maximumWidth(), maximumHeight(), setMaximumSize(), minimumSize() and sizeIncrement().
.SH "int QWidget::maximumWidth () const"
Returns the widget's maximum width.
.PP
See also: maximumSize() and maximumHeight().
.SH "int QWidget::metric ( int m ) const \fC[virtual protected]\fR"
Internal implementation of the virtual QPaintDevice::metric() function.
.PP
Use the QPaintDeviceMetrics class instead.
.PP
Reimplemented from QPaintDevice.
.SH "int QWidget::minimumHeight () const"
Returns the widget's minimum height.
.PP
See also: minimumSize() and minimumWidth().
.SH "QSize QWidget::minimumSize () const"
Returns the minimum widget size.
.PP
The widget cannot be resized to a smaller size than the minimum widget size.
.PP
If the returned minimum size equals (0,0) then it means that there are no constraints on the minimum size. However, Qt does nevertheless not allow you to shrink widgets to less than 1 pixel width/height.
.PP
See also: maximumWidth(), maximumHeight(), setMinimumSize(), maximumSize() and sizeIncrement().
.SH "QSize QWidget::minimumSizeHint () const \fC[virtual]\fR"
Returns a recommended minimum size for the widget, or an invalid size if no minimum size is recommended.
.PP
The default implementation returns an invalid size if there is no layout for this widget, the layout's minimum size otherwise.
.PP
See also: QSize::isValid(), resize(), setMinimumSize() and sizePolicy().
.PP
Reimplemented in QWidgetStack, QSplitter, QLineEdit, QMultiLineEdit, QSlider, QProgressBar, QTabWidget, QListBox, QListView and QScrollView.
.SH "int QWidget::minimumWidth () const"
Returns the widget's minimum width.
.PP
See also: minimumSize() and minimumHeight().
.SH "void QWidget::mouseDoubleClickEvent ( QMouseEvent * e ) \fC[virtual protected]\fR"
This event handler can be reimplemented in a subclass to receive mouse double click events for the widget.
.PP
The default implementation generates a normal mouse press event.
.PP
Note that the widgets gets a mousePressEvent() and a mouseReleaseEvent() before the mouseDoubleClickEvent().
.PP
See also: mousePressEvent(), mouseReleaseEvent(), mouseMoveEvent(), event() and QMouseEvent.
.PP
Reimplemented in QComboBox, QMultiLineEdit, QLineEdit and QListBox.
.SH "QWidget * QWidget::mouseGrabber () \fC[static]\fR"
Returns a pointer to the widget that is currently grabbing the mouse input.
.PP
If no widget in this application is currently grabbing the mouse, 0 is returned.
.PP
See also: grabMouse() and keyboardGrabber().
.SH "void QWidget::mouseMoveEvent ( QMouseEvent * ) \fC[virtual protected]\fR"
This event handler can be reimplemented in a subclass to receive mouse move events for the widget.
.PP
If mouse tracking is switched off, mouse move events only occur if a mouse button is down while the mouse is being moved. If mouse tracking is switched on, mouse move events occur even if no mouse button is down.
.PP
QMouseEvent::pos() reports the position of the mouse cursor, relative to this widget. For press and release events, the position is usually the same as the position of the last mouse move event, but it might be different if the user moves and clicks the mouse fast. This is a feature of the underlying window system, not Qt.
.PP
See also: setMouseTracking(), mousePressEvent(), mouseReleaseEvent(), mouseDoubleClickEvent(), event() and QMouseEvent.
.PP
Reimplemented in QMenuBar, QDial, QListBox, QSlider, QScrollBar, QButton, QPopupMenu, QMultiLineEdit, QSizeGrip, QLineEdit and QComboBox.
.SH "void QWidget::mousePressEvent ( QMouseEvent * e ) \fC[virtual protected]\fR"
This event handler can be reimplemented in a subclass to receive mouse press events for the widget.
.PP
If you create new widgets in the mousePressEvent() the mouseReleaseEvent() may not end up where you expect, depending on the underlying window system (or X11 window manager), the widgets' location and maybe more.
.PP
The default implementation implements the closing of popup widgets when you click outside the window. For other widget types it does nothing.
.PP
See also: mouseReleaseEvent(), mouseDo