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    41 

    42 #include "qcommandlinkbutton.h"

    43 #include "qstylepainter.h"

    44 #include "qstyleoption.h"

    45 #include "qtextdocument.h"

    46 #include "qtextlayout.h"

    47 #include "qcolor.h"

    48 #include "qfont.h"

    49 

    50 #include "private/qpushbutton_p.h"

    51 

    52 QT_BEGIN_NAMESPACE

    53 

    54 /*!

    55     \class QCommandLinkButton

    56     \since 4.4

    57     \brief The QCommandLinkButton widget provides a Vista style command link button.

    58 

    59     \ingroup basicwidgets

    60 

    61 

    62     The command link is a new control that was introduced by Windows Vista. It's

    63     intended use is similar to that of a radio button in that it is used to choose

    64     between a set of mutually exclusive options. Command link buttons should not

    65     be used by themselves but rather as an alternative to radio buttons in

    66     Wizards and dialogs and makes pressing the "next" button redundant.

    67     The appearance is generally similar to that of a flat pushbutton, but

    68     it allows for a descriptive text in addition to the normal button text.

    69     By default it will also carry an arrow icon, indicating that pressing the

    70     control will open another window or page.

    71 

    72     \sa QPushButton QRadioButton

    73 */

    74 

    75 /*!

    76     \property QCommandLinkButton::description

    77     \brief A descriptive label to complement the button text

    78 

    79     Setting this property will set a descriptive text on the

    80     button, complementing the text label. This will usually

    81     be displayed in a smaller font than the primary text.

    82 */

    83 

    84 /*!

    85     \property QCommandLinkButton::flat

    86     \brief This property determines whether the button is displayed as a flat

    87     panel or with a border.

    88 

    89     By default, this property is set to false.

    90 

    91     \sa QPushButton::flat

    92 */

    93 

    94 class QCommandLinkButtonPrivate : public QPushButtonPrivate

    95 {

    96     Q_DECLARE_PUBLIC(QCommandLinkButton)

    97 

    98 public:

    99     QCommandLinkButtonPrivate()

   100         : QPushButtonPrivate(){}

   101 

   102     void init();

   103     qreal titleSize() const;

   104     bool usingVistaStyle() const;

   105 

   106     QFont titleFont() const;

   107     QFont descriptionFont() const;

   108 

   109     QRect titleRect() const;

   110     QRect descriptionRect() const;

   111 

   112     int textOffset() const;

   113     int descriptionOffset() const;

   114     int descriptionHeight(int width) const;

   115     QColor mergedColors(const QColor &a, const QColor &b, int value) const;

   116 

   117     int topMargin() const { return 10; }

   118     int leftMargin() const { return 7; }

   119     int rightMargin() const { return 4; }

   120     int bottomMargin() const { return 4; }

   121 

   122     QString description;

   123     QColor currentColor;

   124 };

   125 

   126 // Mix colors a and b with a ratio in the range [0-255]

   127 QColor QCommandLinkButtonPrivate::mergedColors(const QColor &a, const QColor &b, int value = 50) const

   128 {

   129     Q_ASSERT(value >= 0);

   130     Q_ASSERT(value <= 255);

   131     QColor tmp = a;

   132     tmp.setRed((tmp.red() * value) / 255 + (b.red() * (255 - value)) / 255);

   133     tmp.setGreen((tmp.green() * value) / 255 + (b.green() * (255 - value)) / 255);

   134     tmp.setBlue((tmp.blue() * value) / 255 + (b.blue() * (255 - value)) / 255);

   135     return tmp;

   136 }

   137 

   138 QFont QCommandLinkButtonPrivate::titleFont() const

   139 {

   140     Q_Q(const QCommandLinkButton);

   141     QFont font = q->font();

   142     if (usingVistaStyle()) {

   143         font.setPointSizeF(12.0);

   144     } else {

   145         font.setBold(true);

   146         font.setPointSizeF(9.0);

   147     }

   148 

   149     // Note the font will be resolved against

   150     // QPainters font, so we need to restore the mask

   151     int resolve_mask = font.resolve_mask;

   152     QFont modifiedFont = q->font().resolve(font);

   153     modifiedFont.detach();

   154     modifiedFont.resolve_mask = resolve_mask;

   155     return modifiedFont;

   156 }

   157 

   158 QFont QCommandLinkButtonPrivate::descriptionFont() const

   159 {

   160     Q_Q(const QCommandLinkButton);

   161     QFont font = q->font();

   162     font.setPointSizeF(9.0);

   163 

   164     // Note the font will be resolved against

   165     // QPainters font, so we need to restore the mask

   166     int resolve_mask = font.resolve_mask;

   167     QFont modifiedFont = q->font().resolve(font);

   168     modifiedFont.detach();

   169     modifiedFont.resolve_mask = resolve_mask;

   170     return modifiedFont;

   171 }

   172 

   173 QRect QCommandLinkButtonPrivate::titleRect() const

   174 {

   175     Q_Q(const QCommandLinkButton);

   176     return q->rect().adjusted(textOffset(), topMargin(),

   177                               -rightMargin(), 0);

   178 }

   179 

   180 QRect QCommandLinkButtonPrivate::descriptionRect() const

   181 {

   182     Q_Q(const QCommandLinkButton);

   183     return q->rect().adjusted(textOffset(), descriptionOffset(),

   184                               -rightMargin(), -bottomMargin());

   185 }

   186 

   187 int QCommandLinkButtonPrivate::textOffset() const

   188 {

   189     Q_Q(const QCommandLinkButton);

   190     return q->icon().actualSize(q->iconSize()).width() + leftMargin() + 6;

   191 }

   192 

   193 int QCommandLinkButtonPrivate::descriptionOffset() const

   194 {

   195     QFontMetrics fm(titleFont());

   196     return topMargin() + fm.height();

   197 }

   198 

   199 bool QCommandLinkButtonPrivate::usingVistaStyle() const

   200 {

   201     Q_Q(const QCommandLinkButton);

   202     //### This is a hack to detect if we are indeed running Vista style themed and not in classic

   203     // When we add api to query for this, we should change this implementation to use it.

   204     return q->style()->inherits("QWindowsVistaStyle")

   205         && !q->style()->pixelMetric(QStyle::PM_ButtonShiftHorizontal);

   206 }

   207 

   208 void QCommandLinkButtonPrivate::init()

   209 {

   210     Q_Q(QCommandLinkButton);

   211     QPushButtonPrivate::init();

   212     q->setAttribute(Qt::WA_Hover);

   213 

   214     QSizePolicy policy(QSizePolicy::Preferred, QSizePolicy::Preferred, QSizePolicy::PushButton);

   215     policy.setHeightForWidth(true);

   216     q->setSizePolicy(policy);

   217 

   218     q->setIconSize(QSize(20, 20));

   219     QStyleOptionButton opt;

   220     q->initStyleOption(&opt);

   221     q->setIcon(q->style()->standardIcon(QStyle::SP_CommandLink, &opt));

   222 }

   223 

   224 // Calculates the height of the description text based on widget width

   225 int QCommandLinkButtonPrivate::descriptionHeight(int widgetWidth) const

   226 {

   227     // Calc width of actual paragraph

   228     int lineWidth = widgetWidth - textOffset() - rightMargin();

   229 

   230     qreal descriptionheight = 0;

   231     if (!description.isEmpty()) {

   232         QTextLayout layout(description);

   233         layout.setFont(descriptionFont());

   234         layout.beginLayout();

   235         while (true) {

   236             QTextLine line = layout.createLine();

   237             if (!line.isValid())

   238                 break;

   239             line.setLineWidth(lineWidth);

   240             line.setPosition(QPointF(0, descriptionheight));

   241             descriptionheight += line.height();

   242         }

   243         layout.endLayout();

   244     }

   245     return qRound(descriptionheight);

   246 }

   247 

   248 /*!

   249     \reimp

   250  */

   251 QSize QCommandLinkButton::minimumSizeHint() const

   252 {

   253     Q_D(const QCommandLinkButton);

   254     QSize size = sizeHint();

   255     int minimumHeight = qMax(d->descriptionOffset() + d->bottomMargin(),

   256                              iconSize().height() + d->topMargin());

   257     size.setHeight(minimumHeight);

   258     return size;

   259 }

   260 

   261 /*!

   262     Constructs a command link with no text and a \a parent.

   263 */

   264 

   265 QCommandLinkButton::QCommandLinkButton(QWidget *parent)

   266 : QPushButton(*new QCommandLinkButtonPrivate, parent)

   267 {

   268     Q_D(QCommandLinkButton);

   269     d->init();

   270 }

   271 

   272 /*!

   273     Constructs a command link with the parent \a parent and the text \a

   274     text.

   275 */

   276 

   277 QCommandLinkButton::QCommandLinkButton(const QString &text, QWidget *parent)

   278     : QPushButton(*new QCommandLinkButtonPrivate, parent)

   279 {

   280     Q_D(QCommandLinkButton);

   281     setText(text);

   282     d->init();

   283 }

   284 

   285 /*!

   286     Constructs a command link with a \a text, a \a description, and a \a parent.

   287 */

   288 QCommandLinkButton::QCommandLinkButton(const QString &text, const QString &description, QWidget *parent)

   289     : QPushButton(*new QCommandLinkButtonPrivate, parent)

   290 {

   291     Q_D(QCommandLinkButton);

   292     setText(text);

   293     setDescription(description);

   294     d->init();

   295 }

   296 

   297 /*! \reimp */

   298 bool QCommandLinkButton::event(QEvent *e)

   299 {

   300     return QPushButton::event(e);

   301 }

   302 

   303 /*! \reimp */

   304 QSize QCommandLinkButton::sizeHint() const

   305 {

   306 //  Standard size hints from UI specs

   307 //  Without note: 135, 41

   308 //  With note: 135, 60

   309     Q_D(const QCommandLinkButton);

   310 

   311     QSize size = QPushButton::sizeHint();

   312     QFontMetrics fm(d->titleFont());

   313     int textWidth = qMax(fm.width(text()), 135);

   314     int buttonWidth = textWidth + d->textOffset() + d->rightMargin();

   315     int heightWithoutDescription = d->descriptionOffset() + d->bottomMargin();

   316 

   317     size.setWidth(qMax(size.width(), buttonWidth));

   318     size.setHeight(qMax(d->description.isEmpty() ? 41 : 60,

   319                         heightWithoutDescription + d->descriptionHeight(buttonWidth)));

   320     return size;

   321 }

   322 

   323 /*! \reimp */

   324 int QCommandLinkButton::heightForWidth(int width) const

   325 {

   326     Q_D(const QCommandLinkButton);

   327     int heightWithoutDescription = d->descriptionOffset() + d->bottomMargin();

   328     // find the width available for the description area

   329     return heightWithoutDescription + d->descriptionHeight(width);

   330 }

   331 

   332 /*! \reimp */

   333 void QCommandLinkButton::paintEvent(QPaintEvent *)

   334 {

   335     Q_D(QCommandLinkButton);

   336     QStylePainter p(this);

   337     p.save();

   338 

   339     QStyleOptionButton option;

   340     initStyleOption(&option);

   341 

   342     //Enable command link appearence on Vista

   343     option.features |= QStyleOptionButton::CommandLinkButton;

   344     option.text = QString();

   345     option.icon = QIcon(); //we draw this ourselves

   346     QSize pixmapSize = icon().actualSize(iconSize());

   347 

   348     int vOffset = isDown() ? style()->pixelMetric(QStyle::PM_ButtonShiftVertical) : 0;

   349     int hOffset = isDown() ? style()->pixelMetric(QStyle::PM_ButtonShiftHorizontal) : 0;

   350 

   351     //Draw icon

   352     p.drawControl(QStyle::CE_PushButton, option);

   353     if (!icon().isNull())

   354         p.drawPixmap(d->leftMargin() + hOffset, d->topMargin() + vOffset,

   355         icon().pixmap(pixmapSize, isEnabled() ? QIcon::Normal : QIcon::Disabled,

   356                                   isChecked() ? QIcon::On : QIcon::Off));

   357 

   358     //Draw title

   359     QColor textColor = palette().buttonText().color();

   360     if (isEnabled() && d->usingVistaStyle()) {

   361         textColor = QColor(21, 28, 85);

   362         if (underMouse() && !isDown())

   363             textColor = QColor(7, 64, 229);

   364         //A simple text color transition

   365         d->currentColor = d->mergedColors(textColor, d->currentColor, 60);

   366         option.palette.setColor(QPalette::ButtonText, d->currentColor);

   367     }

   368 

   369     int textflags = Qt::TextShowMnemonic;

   370     if (!style()->styleHint(QStyle::SH_UnderlineShortcut, &option, this))

   371         textflags |= Qt::TextHideMnemonic;

   372 

   373     p.setFont(d->titleFont());

   374     p.drawItemText(d->titleRect().translated(hOffset, vOffset),

   375                     textflags, option.palette, isEnabled(), text(), QPalette::ButtonText);

   376 

   377     //Draw description

   378     textflags |= Qt::TextWordWrap | Qt::ElideRight;

   379     p.setFont(d->descriptionFont());

   380     p.drawItemText(d->descriptionRect().translated(hOffset, vOffset), textflags,

   381                     option.palette, isEnabled(), description(), QPalette::ButtonText);

   382     p.restore();

   383 }

   384 

   385 void QCommandLinkButton::setDescription(const QString &description)

   386 {

   387     Q_D(QCommandLinkButton);

   388     d->description = description;

   389     updateGeometry();

   390     update();

   391 }

   392 

   393 QString QCommandLinkButton::description() const

   394 {

   395     Q_D(const QCommandLinkButton);

   396     return d->description;

   397 }

   398 

   399 QT_END_NAMESPACE

   400