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50
51#include <QtWidgets>
52
53class Widget : public QGraphicsWidget
54{
55public:
56 Widget(const QColor &color, const QColor &textColor, const QString &caption,
57 QGraphicsItem *parent = nullptr)
58 : QGraphicsWidget(parent)
59 , caption(caption)
60 , color(color)
61 , textColor(textColor)
62 {
63 }
64
65 void paint(QPainter *painter, const QStyleOptionGraphicsItem *, QWidget * = nullptr) override
66 {
67 QFont font;
68 font.setPixelSize(0.75 * qMin(a: boundingRect().width(), b: boundingRect().height()));
69
70 painter->fillRect(boundingRect(), color);
71 painter->save();
72 painter->setFont(font);
73 painter->setPen(textColor);
74 painter->drawText(r: boundingRect(), flags: Qt::AlignCenter, text: caption);
75 painter->restore();
76 }
77
78private:
79 QString caption;
80 QColor color;
81 QColor textColor;
82};
83
84int main(int argc, char *argv[])
85{
86 QApplication app(argc, argv);
87
88 QGraphicsScene scene;
89
90 Widget *a = new Widget(Qt::blue, Qt::white, "a");
91 a->setPreferredSize(aw: 100, ah: 100);
92 Widget *b = new Widget(Qt::green, Qt::black, "b");
93 b->setPreferredSize(aw: 100, ah: 100);
94 Widget *c = new Widget(Qt::red, Qt::black, "c");
95 c->setPreferredSize(aw: 100, ah: 100);
96
97 QGraphicsAnchorLayout *layout = new QGraphicsAnchorLayout;
98/*
99 //! [adding a corner anchor in two steps]
100 layout->addAnchor(a, Qt::AnchorTop, layout, Qt::AnchorTop);
101 layout->addAnchor(a, Qt::AnchorLeft, layout, Qt::AnchorLeft);
102 //! [adding a corner anchor in two steps]
103*/
104 //! [adding a corner anchor]
105 layout->addCornerAnchors(firstItem: a, firstCorner: Qt::TopLeftCorner, secondItem: layout, secondCorner: Qt::TopLeftCorner);
106 //! [adding a corner anchor]
107
108 //! [adding anchors]
109 layout->addAnchor(firstItem: b, firstEdge: Qt::AnchorLeft, secondItem: a, secondEdge: Qt::AnchorRight);
110 layout->addAnchor(firstItem: b, firstEdge: Qt::AnchorTop, secondItem: a, secondEdge: Qt::AnchorBottom);
111 //! [adding anchors]
112
113 // Place a third widget below the second.
114 layout->addAnchor(firstItem: b, firstEdge: Qt::AnchorBottom, secondItem: c, secondEdge: Qt::AnchorTop);
115
116/*
117 //! [adding anchors to match sizes in two steps]
118 layout->addAnchor(b, Qt::AnchorLeft, c, Qt::AnchorLeft);
119 layout->addAnchor(b, Qt::AnchorRight, c, Qt::AnchorRight);
120 //! [adding anchors to match sizes in two steps]
121*/
122
123 //! [adding anchors to match sizes]
124 layout->addAnchors(firstItem: b, secondItem: c, orientations: Qt::Horizontal);
125 //! [adding anchors to match sizes]
126
127 // Anchor the bottom-right corner of the third widget to the bottom-right
128 // corner of the layout.
129 layout->addCornerAnchors(firstItem: c, firstCorner: Qt::BottomRightCorner, secondItem: layout, secondCorner: Qt::BottomRightCorner);
130
131 auto w = new QGraphicsWidget(nullptr, Qt::Window | Qt::CustomizeWindowHint | Qt::WindowTitleHint);
132 w->setPos(ax: 20, ay: 20);
133 w->setMinimumSize(aw: 100, ah: 100);
134 w->setPreferredSize(aw: 320, ah: 240);
135 w->setLayout(layout);
136 w->setWindowTitle(QApplication::translate(context: "simpleanchorlayout", key: "QGraphicsAnchorLayout in use"));
137 scene.addItem(item: w);
138
139 QGraphicsView view;
140 view.setScene(&scene);
141 view.setWindowTitle(QApplication::translate(context: "simpleanchorlayout", key: "Simple Anchor Layout"));
142
143 view.resize(w: 360, h: 320);
144 view.show();
145
146 return app.exec();
147}
148

source code of qtbase/examples/widgets/graphicsview/simpleanchorlayout/main.cpp