qpushbutton.cpp

qtopia-phone-2.2.0下公共的控件实现源代码。

/****************************************************************************
** $Id: qt/src/widgets/qpushbutton.cpp   2.3.12   edited 2005-10-27 $
**
** Implementation of QPushButton class
**
** Created : 940221
**
** Copyright (C) 1992-2000 Trolltech AS.  All rights reserved.
**
** This file is part of the widgets module of the Qt GUI Toolkit.
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** LICENSE.QPL included in the packaging of this file.
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** This file may be distributed and/or modified under the terms of the
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** Foundation and appearing in the file LICENSE.GPL included in the
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#include "qpushbutton.h"
#ifndef QT_NO_PUSHBUTTON
#include "qdialog.h"
#include "qfontmetrics.h"
#include "qpainter.h"
#include "qdrawutil.h"
#include "qpixmap.h"
#include "qbitmap.h"
#include "qpopupmenu.h"
#include "qguardedptr.h"
#include "qptrdict.h" // binary compatibility
#include "qapplication.h"
#include "qtoolbar.h"

// NOT REVISED
/*!
  \class QPushButton qpushbutton.h
  \brief The QPushButton widget provides a command button.

  \ingroup basic

  The push button, also referred to as command button, is perhaps the
  most central widget in any graphical user interface: Push it to
  command the computer to perform some action. Typical actions are Ok,
  Apply, Cancel, Close or Help.

  A command button is rectangular (ca. 80x22 pixel) and typically
  displays a text label describing its action. An underscored
  character in the label, marked with an ampersand in the text,
  signals an accelerator key.

  This code creates a push button labelled "Rock & Roll".  Due to the
  first ampersand, the c displays underscored and the button gets the
  automatic accelerator key, Alt-C:

  \code
    QPushButton *p = new QPushButton( "Ro&ck && Roll", this );
  \endcode

  The text can be changed anytime later with setText(). You can also
  define a pixmap with setPixmap(). The text/pixmap is manipulated as
  necessary to create "disabled" appearance according to the
  respective GUI style when the button is disabled. A command button
  can, in addition to the text or pixmap label, also display a little
  icon. Use the extended constructor or setIconSet() to define this
  icon.

  A push button emits the signal clicked() when it is activated,
  either with the mouse, the spacebar or a keyboard accelerator.
  Connect to this signal to perform the button's action.  Other
  signals of less importance are pressed() when the button is pressed
  down and released() when it is released, respectively.

  Command buttons in dialogs are by default auto-default buttons,
  i.e. they become the default push button automatically when they
  receive the keyboard input focus. A default button is a command
  button that is activated when the users hits the Enter or Return key
  in a dialog. Adjust this behaviour with setAutoDefault(). Note that
  auto-default buttons reserve a little extra space necessary to draw
  a default-button indicator. If you do not want this space around
  your buttons, call setAutoDefault( FALSE ).

  Being so central, the widget has grown to accomodate a great many
  variations in the past decade, and by now the Microsoft style guide
  shows about ten different states of Windows push buttons, and the
  text implies that there are dozens more when all the combinations of
  features are taken into consideration.

  The most important modes or states are, sorted roughly by importance: <ul>
  <li> Available or not ("grayed out", disabled).
  <li> Standard push button, toggling push button or menu button.
  <li> On or off (only for toggling push buttons).
  <li> Default or normal.  The default button in a dialog can
  generally be "clicked" using the Enter or Return key.
  <li> Auto-repeat or not.
  <li> Pressed down or not.
  </ul>

  As a general rule, use a push button when the application or dialog
  window performs an action when the user clicks on it (like Apply,
  Cancel, Close, Help, ...) \e and when the widget is supposed to have
  a wide, rectangular shape with a text label.  Small, typically
  square buttons that change the state of the window rather than
  performing an action (like for example the buttons in the top/right
  corner of the QFileDialog), are not command buttons, but tool
  buttons. Qt provides a special class QToolButton for these.

  Also, if you need toggle behaviour (see setToggleButton()) or a button
  that auto-repeats the activation signal when being pushed down like
  the arrows in a scrollbar (see setAutoRepeat()), a command button is
  probably not what you want. In case of doubt, go with a tool button.

  A variation of a command button is a menu button. It provides not
  just one command, but several. Use the method setPopup() to
  associate a popup menu with a push button.

  Other classes of buttons are option buttons (see QRadioButton) and
  check boxes (see QCheckBox).

  <img src="qpushbt-m.png"> <img src="qpushbt-w.png">

  In Qt, the QButton class provides most of the modes and other API,
  and QPushButton provides GUI logic.  See QButton for more
  information about the API.

  \important text, setText, text, pixmap, setPixmap, accel, setAccel,
  isToggleButton, setDown, isDown, isOn, state, autoRepeat,
  isExclusiveToggle, group, setAutoRepeat, toggle, pressed, released,
  clicked, toggled, state stateChanged

  \sa QToolButton, QRadioButton QCheckBox
  <a href="guibooks.html#fowler">GUI Design Handbook: Push Button</a>
*/


class QPushButtonPrivate
{
public:
    QPushButtonPrivate()
	:iconset( 0 )
    {}
    ~QPushButtonPrivate()
    {
	delete iconset;
    }
    QGuardedPtr<QPopupMenu> popup;
    QIconSet* iconset;
};

static QPtrDict<QPushButtonPrivate> *d_ptr = 0;
static void cleanup_d_ptr()
{
    delete d_ptr;
    d_ptr = 0;
}
static QPushButtonPrivate* d( const QPushButton* foo )
{
    if ( !d_ptr ) {
	d_ptr = new QPtrDict<QPushButtonPrivate>;
	d_ptr->setAutoDelete( TRUE );
	qAddPostRoutine( cleanup_d_ptr );
    }
    QPushButtonPrivate* ret = d_ptr->find( (void*)foo );
    if ( ! ret ) {
	ret = new QPushButtonPrivate;
	d_ptr->replace( (void*) foo, ret );
    }
    return ret;
}

static bool has_d( const QPushButton* foo )
{
    return d_ptr && d_ptr->find( (void*)foo );
}

static void delete_d( const QPushButton* foo )
{
    if ( d_ptr )
	d_ptr->remove( (void*) foo );
}



/*!
  Constructs a push button with no text.

  The \a parent and \a name arguments are sent to the QWidget constructor.
*/

QPushButton::QPushButton( QWidget *parent, const char *name )
	: QButton( parent, name )
{
    init();
}

/*!
  Constructs a push button with a text.

  The \a parent and \a name arguments are sent to the QWidget constructor.
*/

QPushButton::QPushButton( const QString &text, QWidget *parent,
			  const char *name )
	: QButton( parent, name )
{
    init();
    setText( text );
}


/*!
  Constructs a push button with an \a icon and a \a text.

  Note that you can also pass a QPixmap object as icon (thanks to C++'
  implicit type conversion).

  The \a parent and \a name arguments are sent to the QWidget constructor.
*/

QPushButton::QPushButton( const QIconSet& icon, const QString &text,
			  QWidget *parent, const char *name )
	: QButton( parent, name )
{
    init();
    setText( text );
    setIconSet( icon );
}



/*!
  Destructs the push button
 */
QPushButton::~QPushButton()
{
    delete_d( this );
}

void QPushButton::init()
{
    defButton = FALSE;
    lastEnabled = FALSE;
    hasMenuArrow = FALSE;
    flt = FALSE;
#ifndef QT_NO_DIALOG
    autoDefButton = topLevelWidget()->inherits("QDialog");
#else
    autoDefButton = FALSE;
#endif
    setBackgroundMode( PaletteButton );
    setSizePolicy( QSizePolicy( QSizePolicy::Minimum, QSizePolicy::Fixed ) );
}


/*!
  Makes the push button a toggle button if \a enable is TRUE, or a normal
  push button if \a enable is FALSE.

  Toggle buttons have an on/off state similar to \link QCheckBox check
  boxes. \endlink A push button is initially not a toggle button.

  \sa setOn(), toggle(), isToggleButton() toggled()
*/

void QPushButton::setToggleButton( bool enable )
{
    QButton::setToggleButton( enable );
}


/*!
  Switches a toggle button on if \a enable is TRUE or off if \a enable is
  FALSE.
  \sa isOn(), toggle(), toggled(), isToggleButton()
*/

void QPushButton::setOn( bool enable )
{
    if ( !isToggleButton() )
	return;
    QButton::setOn( enable );
}


/*!
  Toggles the state of a toggle button.
  \sa isOn(), setOn(), toggled(), isToggleButton()
*/

void QPushButton::toggle()
{
    if ( !isToggleButton() )
	return;
    QButton::setOn( !isOn() );
}


/*! \fn bool QPushButton::autoDefault() const

  Returns TRUE if the button is an auto-default button.

  \sa setAutoDefault()
*/

/*!
  Sets the push buttons to an auto-default button if \a enable is TRUE,
  or to a normal button if \a enable is FALSE.

  An auto-default button becomes automatically the default push button
  in a dialog when it receives the keyboard input focus.

  In some GUI styles, a default button is drawn with an extra frame
  around it, up to 3 pixels or more. Qt automatically keeps this space
  free around auto-default buttons, i.e. auto-default buttons may have
  a slightly larger size hint.

  \sa autoDefault(), setDefault()
*/

void QPushButton::setAutoDefault( bool enable )
{
    if ( (bool)autoDefButton == enable )
	return;
    autoDefButton = enable;
    update();
    updateGeometry();
}


/*!
  \fn bool QPushButton::isDefault() const
  Returns TRUE if the button is currently default.

  \sa setDefault()
*/

/*!
  Sets this button to be the current default button of a
  \link QDialog dialog\endlink if \a enable is TRUE, or to be a normal button
  if \a enable is FALSE.

  The current default button gets clicked when the user presses the
  "Enter" key, independently of which widget in the dialog currently
  has the keyboard input focus.  Only one push button can at any time
  be the default button.  This button is then displayed with an
  additional frame ( depending on the GUI style ).

  The default button behaviour is only provided in dialogs. Buttons
  can always be clicked from the keyboard by pressing return or the
  spacebar when the button has focus.

  \sa isDefault(), setAutoDefault(), QDialog
*/

void QPushButton::setDefault( bool enable )
{
    if ( (bool)defButton == enable )
	return;					// no change
    defButton = enable;
#ifndef QT_NO_DIALOG
    if ( defButton && topLevelWidget()->inherits( "QDialog" ) )
 	((QDialog*)topLevelWidget())->setDefault( this );
#endif
    update();
}


/*!\reimp
*/
QSize QPushButton::sizeHint() const
{
    constPolish();
    int w = 0;
    int h = 0;

    if ( pixmap() ) {
	QPixmap *pm = (QPixmap *)pixmap();
	w = pm->width() + style().buttonMargin();