Developer Documentation
QtGraphicsButton.cc
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41 
42 
43 
44 
45 
46 //=============================================================================
47 //
48 // CLASS QtGraphicsButton - IMPLEMENTATION
49 //
50 //=============================================================================
51 
52 //== INCLUDES =================================================================
53 
54 #include <QPainter>
55 #include <QGraphicsSceneMouseEvent>
56 
57 #include "QtGraphicsButton.hh"
58 
59 //== IMPLEMENTATION ==========================================================
60 
61 QtGraphicsButton::QtGraphicsButton (const QImage &_image, QGraphicsItem *_parent, int _width, int _height) :
62  QGraphicsItem (_parent),
63  checkable_(false),
64  checked_(false),
65  pressed_(false),
66  over_(false),
67  width_(_width),
68  height_(_height)
69 {
70  if (width_ <= 0)
71  width_ = _image.width ();
72  if (height_ <= 0)
73  height_ = _image.height ();
74 
75  // scale image to button dimensions
76  QImage i = _image.scaled (width_, height_, Qt::IgnoreAspectRatio, Qt::SmoothTransformation).convertToFormat (QImage::Format_ARGB32);
77 
78  checkedPix_ = QPixmap::fromImage (i);
79 
80  // generate black/white and transparent images for the other button states
81  QImage normal (width_, height_, QImage::Format_ARGB32);
82  QImage over (width_, height_, QImage::Format_ARGB32);
83 
84  for (int x = 0; x < width_; x++)
85  for (int y = 0; y < height_; y++)
86  {
87  QRgb pix = i.pixel (x, y);
88  over.setPixel (x, y, qRgba (qRed (pix), qGreen (pix), qBlue (pix), qAlpha (pix) * 0.5));
89  normal.setPixel (x, y, qRgba (qGray (pix), qGray (pix), qGray (pix), qAlpha (pix) * 0.3));
90  }
91  overPix_ = QPixmap::fromImage (over);
92  normalPix_ = QPixmap::fromImage (normal);
93 
94  setAcceptHoverEvents (true);
95 }
96 
97 //-----------------------------------------------------------------------------
98 
100 {
101  return QRectF (QPointF(0, 0), QSizeF (width_, height_));
102 }
103 
104 //-----------------------------------------------------------------------------
105 
106 void QtGraphicsButton::paint (QPainter *_painter, const QStyleOptionGraphicsItem *, QWidget *)
107 {
108  _painter->setClipping (false);
109  if (pressed_ || checked_)
110  _painter->drawPixmap (0, 0, checkedPix_);
111  else if (over_)
112  _painter->drawPixmap (0, 0, overPix_);
113  else
114  _painter->drawPixmap (0, 0, normalPix_);
115 }
116 
117 //-----------------------------------------------------------------------------
118 
120 {
121  checkable_ = _value;
122 }
123 
124 //-----------------------------------------------------------------------------
125 
127 {
128  checked_ = _value;
129 }
130 
131 //-----------------------------------------------------------------------------
132 
134 {
135  return checked_;
136 }
137 
138 //-----------------------------------------------------------------------------
139 
140 void QtGraphicsButton::hoverEnterEvent (QGraphicsSceneHoverEvent *)
141 {
142  over_ = true;
143  update ();
144 }
145 
146 //-----------------------------------------------------------------------------
147 
148 void QtGraphicsButton::hoverLeaveEvent (QGraphicsSceneHoverEvent *)
149 {
150  over_ = false;
151  update ();
152 }
153 
154 //-----------------------------------------------------------------------------
155 
156 void QtGraphicsButton::mousePressEvent ( QGraphicsSceneMouseEvent *_event)
157 {
158  _event->accept ();
159  pressed_ = true;
160  if (checkable_)
161  checked_ = !checked_;
162  update ();
163 
164  emit pressed ();
165 }
166 
167 //-----------------------------------------------------------------------------
168 
169 void QtGraphicsButton::mouseReleaseEvent (QGraphicsSceneMouseEvent *_event)
170 {
171  _event->accept ();
172  pressed_ = false;
173  update ();
174 }
175 
176 //-----------------------------------------------------------------------------
177 
178 QVariant QtGraphicsButton::itemChange (GraphicsItemChange _change, const QVariant &_value)
179 {
180  // reset state if button was hidden
181  if (_change == QGraphicsItem::ItemVisibleHasChanged)
182  {
183  pressed_ = false;
184  over_ = false;
185  }
186  return QGraphicsItem::itemChange (_change, _value);
187 }
188 
189 //=============================================================================
void setChecked(bool _value)
sets button checked state
virtual QRectF boundingRect() const
returns the bounding rect
QtGraphicsButton(const QImage &_image, QGraphicsItem *_parent=0, int _width=-1, int _height=-1)
bool checkable_
button state
QPixmap normalPix_
pixmaps for different button states
virtual void hoverEnterEvent(QGraphicsSceneHoverEvent *_event)
event tracking
int width_
button size
bool isChecked() const
returns button checked state
virtual void paint(QPainter *_painter, const QStyleOptionGraphicsItem *_option, QWidget *_widget=0)
paints the button
void pressed()
signals a button press
void setCheckable(bool _value)
makes the button checkable