CharacterWidget Class Reference

#include <characterwidget.h>

Inheritance diagram for CharacterWidget:

[legend]Collaboration diagram for CharacterWidget:

[legend]List of all members.

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Detailed Description

Definition at line 36 of file characterwidget.h.

Public Slots
void	updateFont (const QFont &font)
void	updateSize (const QString &fontSize)
void	updateStyle (const QString &fontStyle)
void	updateFontMerging (bool enable)
Signals
void	characterSelected (const QString &character)
Public Member Functions
	CharacterWidget (QWidget *parent=0)
QSize	sizeHint () const
Protected Member Functions
void	mouseMoveEvent (QMouseEvent *event)
void	mousePressEvent (QMouseEvent *event)
void	paintEvent (QPaintEvent *event)
Private Attributes
QFont	displayFont
int	columns
int	lastKey
int	squareSize

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Constructor & Destructor Documentation

CharacterWidget::CharacterWidget

(

QWidget *

parent = 0

)

Definition at line 28 of file characterwidget.cpp.

References columns, lastKey, QWidget::setMouseTracking(), and squareSize.

    : QWidget(parent)
{
    squareSize = 24;
    columns = 16;
    lastKey = -1;
    setMouseTracking(true);
}

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Member Function Documentation

QSize CharacterWidget::sizeHint

(

)

const [virtual]

Reimplemented from QWidget.

Definition at line 74 of file characterwidget.cpp.

References columns, and squareSize.

{
    return QSize(columns*squareSize, (65536/columns)*squareSize);
}

void CharacterWidget::updateFont

(

const QFont &

font

)

[slot]

Definition at line 37 of file characterwidget.cpp.

References QWidget::adjustSize(), displayFont, QFont::family(), QWidget::font(), QWidget::QFontMetrics, qMax(), QFont::setFamily(), squareSize, and QWidget::update().

{
    displayFont.setFamily(font.family());
    squareSize = qMax(24, QFontMetrics(displayFont).xHeight() * 3);
    adjustSize();
    update();
}

void CharacterWidget::updateSize

(

const QString &

fontSize

)

[slot]

Definition at line 45 of file characterwidget.cpp.

References QWidget::adjustSize(), displayFont, QWidget::QFontMetrics, qMax(), QFont::setPointSize(), squareSize, QString::toInt(), and QWidget::update().

{
    displayFont.setPointSize(fontSize.toInt());
    squareSize = qMax(24, QFontMetrics(displayFont).xHeight() * 3);
    adjustSize();
    update();
}

void CharacterWidget::updateStyle

(

const QString &

fontStyle

)

[slot]

Definition at line 53 of file characterwidget.cpp.

References QWidget::adjustSize(), displayFont, QFont::family(), QFontDatabase::font(), QFont::pointSize(), QWidget::QFontMetrics, qMax(), QFont::setStyleStrategy(), squareSize, QFont::styleStrategy(), and QWidget::update().

{
    QFontDatabase fontDatabase;
    const QFont::StyleStrategy oldStrategy = displayFont.styleStrategy();
    displayFont = fontDatabase.font(displayFont.family(), fontStyle, displayFont.pointSize());
    displayFont.setStyleStrategy(oldStrategy);
    squareSize = qMax(24, QFontMetrics(displayFont).xHeight() * 3);
    adjustSize();
    update();
}

void CharacterWidget::updateFontMerging

(

bool

enable

)

[slot]

Definition at line 64 of file characterwidget.cpp.

References QWidget::adjustSize(), displayFont, QFont::NoFontMerging, QFont::PreferDefault, QFont::setStyleStrategy(), and QWidget::update().

{
    if (enable)
        displayFont.setStyleStrategy(QFont::PreferDefault);
    else
        displayFont.setStyleStrategy(QFont::NoFontMerging);
    adjustSize();
    update();
}

void CharacterWidget::characterSelected

(

const QString &

character

)

[signal]

Referenced by mousePressEvent().

void CharacterWidget::mouseMoveEvent

(

QMouseEvent *

event

)

[protected, virtual]

This event handler, for event event, can be reimplemented in a subclass to receive mouse move events for the widget.

If mouse tracking is switched off, mouse move events only occur if a mouse button is pressed while the mouse is being moved. If mouse tracking is switched on, mouse move events occur even if no mouse button is pressed.

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's hand shakes. This is a feature of the underlying window system, not Qt.

See also:

setMouseTracking(), mousePressEvent(), mouseReleaseEvent(), mouseDoubleClickEvent(), event(), QMouseEvent, {Scribble Example}

Reimplemented from QWidget.

Definition at line 79 of file characterwidget.cpp.

References QString::arg(), columns, displayFont, QWidget::event(), QFont::family(), QString::fromLatin1(), key, QWidget::mapFromGlobal(), QString::number(), QToolTip::showText(), squareSize, QPoint::x(), and QPoint::y().

{
    QPoint widgetPosition = mapFromGlobal(event->globalPos());
    uint key = (widgetPosition.y()/squareSize)*columns + widgetPosition.x()/squareSize;

    QString text = QString::fromLatin1("<p>Character: <span style=\"font-size: 24pt; font-family: %1\">").arg(displayFont.family())
                  + QChar(key)
                  + QString::fromLatin1("</span><p>Value: 0x")
                  + QString::number(key, 16);
    QToolTip::showText(event->globalPos(), text, this);
}

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void CharacterWidget::mousePressEvent

(

QMouseEvent *

event

)

[protected, virtual]

This event handler, for event event, can be reimplemented in a subclass to receive mouse press events for the widget.

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.

The default implementation implements the closing of popup widgets when you click outside the window. For other widget types it does nothing.

See also:

mouseReleaseEvent(), mouseDoubleClickEvent(), mouseMoveEvent(), event(), QMouseEvent, {Scribble Example}

Reimplemented from QWidget.

Definition at line 91 of file characterwidget.cpp.

References QUnicodeTables::category(), characterSelected(), columns, emit, QWidget::event(), lastKey, Qt::LeftButton, QWidget::mousePressEvent(), QChar::NoCategory, squareSize, and QWidget::update().

{
    if (event->button() == Qt::LeftButton) {
        lastKey = (event->y()/squareSize)*columns + event->x()/squareSize;
        if (QChar(lastKey).category() != QChar::NoCategory)
            emit characterSelected(QString(QChar(lastKey)));
        update();
    }
    else
        QWidget::mousePressEvent(event);
}

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void CharacterWidget::paintEvent

(

QPaintEvent *

event

)

[protected, virtual]

This event handler can be reimplemented in a subclass to receive paint events which are passed in the event parameter.

A paint event is a request to repaint all or part of the widget. It can happen as a result of repaint() or update(), or because the widget was obscured and has now been uncovered, or for many other reasons.

Many widgets can simply repaint their entire surface when asked to, but some slow widgets need to optimize by painting only the requested region: QPaintEvent::region(). This speed optimization does not change the result, as painting is clipped to that region during event processing. QListView and QTableView do this, for example.

Qt also tries to speed up painting by merging multiple paint events into one. When update() is called several times or the window system sends several paint events, Qt merges these events into one event with a larger region (see QRegion::united()). repaint() does not permit this optimization, so we suggest using update() whenever possible.

When the paint event occurs, the update region has normally been erased, so that you're painting on the widget's background.

The background can be set using setBackgroundRole() and setPalette().

From Qt 4.0, QWidget automatically double-buffers its painting, so there's no need to write double-buffering code in paintEvent() to avoid flicker.

Note: Under X11 it is possible to toggle the global double buffering by calling qt_x11_set_global_double_buffer(). Example usage:

    ...
    extern void qt_x11_set_global_double_buffer(bool);
    qt_x11_set_global_double_buffer(false);
    ...

See also:

event(), repaint(), update(), QPainter, QPixmap, QPaintEvent, {Analog Clock Example}

Reimplemented from QWidget.

Definition at line 103 of file characterwidget.cpp.

References QFontMetrics::ascent(), Qt::black, QRect::bottom(), columns, displayFont, QPainter::drawRect(), QPainter::drawText(), QWidget::event(), QPainter::fillRect(), QWidget::fontMetrics(), Qt::gray, key, lastKey, QRect::left(), Qt::red, QRect::right(), row, QPainter::setClipRect(), QPainter::setFont(), QPainter::setPen(), squareSize, QRect::top(), Qt::white, and QFontMetrics::width().

{
    QPainter painter(this);
    painter.fillRect(event->rect(), QBrush(Qt::white));
    painter.setFont(displayFont);

    QRect redrawRect = event->rect();
    int beginRow = redrawRect.top()/squareSize;
    int endRow = redrawRect.bottom()/squareSize;
    int beginColumn = redrawRect.left()/squareSize;
    int endColumn = redrawRect.right()/squareSize;

    painter.setPen(QPen(Qt::gray));
    for (int row = beginRow; row <= endRow; ++row) {
        for (int column = beginColumn; column <= endColumn; ++column) {
            painter.drawRect(column*squareSize, row*squareSize, squareSize, squareSize);
        }
    }

    QFontMetrics fontMetrics(displayFont);
    painter.setPen(QPen(Qt::black));
    for (int row = beginRow; row <= endRow; ++row) {

        for (int column = beginColumn; column <= endColumn; ++column) {

            int key = row*columns + column;
            painter.setClipRect(column*squareSize, row*squareSize, squareSize, squareSize);

            if (key == lastKey)
                painter.fillRect(column*squareSize + 1, row*squareSize + 1, squareSize, squareSize, QBrush(Qt::red));

            painter.drawText(column*squareSize + (squareSize / 2) - fontMetrics.width(QChar(key))/2,
                             row*squareSize + 4 + fontMetrics.ascent(),
                             QString(QChar(key)));
        }
    }
}

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Member Data Documentation

QFont CharacterWidget::displayFont [private]

Definition at line 59 of file characterwidget.h.

Referenced by mouseMoveEvent(), paintEvent(), updateFont(), updateFontMerging(), updateSize(), and updateStyle().

int CharacterWidget::columns [private]

Definition at line 60 of file characterwidget.h.

Referenced by CharacterWidget(), mouseMoveEvent(), mousePressEvent(), paintEvent(), and sizeHint().

int CharacterWidget::lastKey [private]

Definition at line 61 of file characterwidget.h.

Referenced by CharacterWidget(), mousePressEvent(), and paintEvent().

int CharacterWidget::squareSize [private]

Definition at line 62 of file characterwidget.h.

Referenced by CharacterWidget(), mouseMoveEvent(), mousePressEvent(), paintEvent(), sizeHint(), updateFont(), updateSize(), and updateStyle().

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The documentation for this class was generated from the following files:

• examples/widgets/charactermap/characterwidget.h
• examples/widgets/charactermap/characterwidget.cpp

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