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50
51
52#include "mainwindow.h"
53#include "interfaces.h"
54#include "paintarea.h"
55#include "plugindialog.h"
56
57#include <QAction>
58#include <QActionGroup>
59#include <QApplication>
60#include <QColorDialog>
61#include <QFileDialog>
62#include <QInputDialog>
63#include <QMenu>
64#include <QMenuBar>
65#include <QMessageBox>
66#include <QPluginLoader>
67#include <QScrollArea>
68#include <QTimer>
69
70MainWindow::MainWindow() : paintArea(new PaintArea)
71 , scrollArea(new QScrollArea)
72{
73 scrollArea->setBackgroundRole(QPalette::Dark);
74 scrollArea->setWidget(paintArea);
75 setCentralWidget(scrollArea);
76
77 createActions();
78 createMenus();
79 loadPlugins();
80
81 setWindowTitle(tr(s: "Plug & Paint"));
82
83 if (!brushActionGroup->actions().isEmpty())
84 brushActionGroup->actions().first()->trigger();
85
86 QTimer::singleShot(interval: 500, receiver: this, slot: &MainWindow::aboutPlugins);
87}
88
89void MainWindow::open()
90{
91 const QString fileName = QFileDialog::getOpenFileName(parent: this,
92 caption: tr(s: "Open File"),
93 dir: QDir::currentPath());
94 if (!fileName.isEmpty()) {
95 if (!paintArea->openImage(fileName)) {
96 QMessageBox::information(parent: this, title: tr(s: "Plug & Paint"),
97 text: tr(s: "Cannot load %1.").arg(a: fileName));
98 return;
99 }
100 paintArea->adjustSize();
101 }
102}
103
104bool MainWindow::saveAs()
105{
106 const QString initialPath = QDir::currentPath() + "/untitled.png";
107
108 const QString fileName = QFileDialog::getSaveFileName(parent: this, caption: tr(s: "Save As"),
109 dir: initialPath);
110 if (fileName.isEmpty())
111 return false;
112
113 return paintArea->saveImage(fileName, fileFormat: "png");
114}
115
116void MainWindow::brushColor()
117{
118 const QColor newColor = QColorDialog::getColor(initial: paintArea->brushColor());
119 if (newColor.isValid())
120 paintArea->setBrushColor(newColor);
121}
122
123void MainWindow::brushWidth()
124{
125 bool ok;
126 const int newWidth = QInputDialog::getInt(parent: this, title: tr(s: "Plug & Paint"),
127 label: tr(s: "Select brush width:"),
128 value: paintArea->brushWidth(),
129 minValue: 1, maxValue: 50, step: 1, ok: &ok);
130 if (ok)
131 paintArea->setBrushWidth(newWidth);
132}
133
134//! [0]
135void MainWindow::changeBrush()
136{
137 auto action = qobject_cast<QAction *>(object: sender());
138 if (!action)
139 return;
140 auto iBrush = qobject_cast<BrushInterface *>(object: action->parent());
141 if (!iBrush)
142 return;
143 const QString brush = action->text();
144
145 paintArea->setBrush(brushInterface: iBrush, brush);
146}
147//! [0]
148
149//! [1]
150void MainWindow::insertShape()
151{
152 auto action = qobject_cast<QAction *>(object: sender());
153 if (!action)
154 return;
155 auto iShape = qobject_cast<ShapeInterface *>(object: action->parent());
156 if (!iShape)
157 return;
158
159 const QPainterPath path = iShape->generateShape(shape: action->text(), parent: this);
160 if (!path.isEmpty())
161 paintArea->insertShape(path);
162}
163//! [1]
164
165//! [2]
166void MainWindow::applyFilter()
167{
168 auto action = qobject_cast<QAction *>(object: sender());
169 if (!action)
170 return;
171 auto iFilter = qobject_cast<FilterInterface *>(object: action->parent());
172 if (!iFilter)
173 return;
174
175 const QImage image = iFilter->filterImage(filter: action->text(), image: paintArea->image(),
176 parent: this);
177 paintArea->setImage(image);
178}
179//! [2]
180
181void MainWindow::about()
182{
183 QMessageBox::about(parent: this, title: tr(s: "About Plug & Paint"),
184 text: tr(s: "The <b>Plug & Paint</b> example demonstrates how to write Qt "
185 "applications that can be extended through plugins."));
186}
187
188//! [3]
189void MainWindow::aboutPlugins()
190{
191 PluginDialog dialog(pluginsDir.path(), pluginFileNames, this);
192 dialog.exec();
193}
194//! [3]
195
196void MainWindow::createActions()
197{
198 openAct = new QAction(tr(s: "&Open..."), this);
199 openAct->setShortcuts(QKeySequence::Open);
200 connect(sender: openAct, signal: &QAction::triggered, receiver: this, slot: &MainWindow::open);
201
202 saveAsAct = new QAction(tr(s: "&Save As..."), this);
203 saveAsAct->setShortcuts(QKeySequence::SaveAs);
204 connect(sender: saveAsAct, signal: &QAction::triggered, receiver: this, slot: &MainWindow::saveAs);
205
206 exitAct = new QAction(tr(s: "E&xit"), this);
207 exitAct->setShortcuts(QKeySequence::Quit);
208 connect(sender: exitAct, signal: &QAction::triggered, receiver: this, slot: &MainWindow::close);
209
210 brushColorAct = new QAction(tr(s: "&Brush Color..."), this);
211 connect(sender: brushColorAct, signal: &QAction::triggered, receiver: this, slot: &MainWindow::brushColor);
212
213 brushWidthAct = new QAction(tr(s: "&Brush Width..."), this);
214 connect(sender: brushWidthAct, signal: &QAction::triggered, receiver: this, slot: &MainWindow::brushWidth);
215
216 brushActionGroup = new QActionGroup(this);
217
218 aboutAct = new QAction(tr(s: "&About"), this);
219 connect(sender: aboutAct, signal: &QAction::triggered, receiver: this, slot: &MainWindow::about);
220
221 aboutQtAct = new QAction(tr(s: "About &Qt"), this);
222 connect(sender: aboutQtAct, signal: &QAction::triggered, qApp, slot: &QApplication::aboutQt);
223
224 aboutPluginsAct = new QAction(tr(s: "About &Plugins"), this);
225 connect(sender: aboutPluginsAct, signal: &QAction::triggered, receiver: this, slot: &MainWindow::aboutPlugins);
226}
227
228void MainWindow::createMenus()
229{
230 fileMenu = menuBar()->addMenu(title: tr(s: "&File"));
231 fileMenu->addAction(action: openAct);
232 fileMenu->addAction(action: saveAsAct);
233 fileMenu->addSeparator();
234 fileMenu->addAction(action: exitAct);
235
236 brushMenu = menuBar()->addMenu(title: tr(s: "&Brush"));
237 brushMenu->addAction(action: brushColorAct);
238 brushMenu->addAction(action: brushWidthAct);
239 brushMenu->addSeparator();
240
241 shapesMenu = menuBar()->addMenu(title: tr(s: "&Shapes"));
242
243 filterMenu = menuBar()->addMenu(title: tr(s: "&Filter"));
244
245 menuBar()->addSeparator();
246
247 helpMenu = menuBar()->addMenu(title: tr(s: "&Help"));
248 helpMenu->addAction(action: aboutAct);
249 helpMenu->addAction(action: aboutQtAct);
250 helpMenu->addAction(action: aboutPluginsAct);
251}
252
253//! [4]
254void MainWindow::loadPlugins()
255{
256 const auto staticInstances = QPluginLoader::staticInstances();
257 for (QObject *plugin : staticInstances)
258 populateMenus(plugin);
259//! [4] //! [5]
260
261 pluginsDir = QDir(QCoreApplication::applicationDirPath());
262
263#if defined(Q_OS_WIN)
264 if (pluginsDir.dirName().toLower() == "debug" || pluginsDir.dirName().toLower() == "release")
265 pluginsDir.cdUp();
266#elif defined(Q_OS_MAC)
267 if (pluginsDir.dirName() == "MacOS") {
268 pluginsDir.cdUp();
269 pluginsDir.cdUp();
270 pluginsDir.cdUp();
271 }
272#endif
273 pluginsDir.cd(dirName: "plugins");
274//! [5]
275
276//! [6]
277 const auto entryList = pluginsDir.entryList(filters: QDir::Files);
278 for (const QString &fileName : entryList) {
279 QPluginLoader loader(pluginsDir.absoluteFilePath(fileName));
280 QObject *plugin = loader.instance();
281 if (plugin) {
282 populateMenus(plugin);
283 pluginFileNames += fileName;
284//! [6] //! [7]
285 }
286//! [7] //! [8]
287 }
288//! [8]
289
290//! [9]
291 brushMenu->setEnabled(!brushActionGroup->actions().isEmpty());
292 shapesMenu->setEnabled(!shapesMenu->actions().isEmpty());
293 filterMenu->setEnabled(!filterMenu->actions().isEmpty());
294}
295//! [9]
296
297//! [10]
298void MainWindow::populateMenus(QObject *plugin)
299{
300 auto iBrush = qobject_cast<BrushInterface *>(object: plugin);
301 if (iBrush)
302 addToMenu(plugin, texts: iBrush->brushes(), menu: brushMenu, member: &MainWindow::changeBrush,
303 actionGroup: brushActionGroup);
304
305 auto iShape = qobject_cast<ShapeInterface *>(object: plugin);
306 if (iShape)
307 addToMenu(plugin, texts: iShape->shapes(), menu: shapesMenu, member: &MainWindow::insertShape);
308
309 auto iFilter = qobject_cast<FilterInterface *>(object: plugin);
310 if (iFilter)
311 addToMenu(plugin, texts: iFilter->filters(), menu: filterMenu, member: &MainWindow::applyFilter);
312}
313//! [10]
314
315void MainWindow::addToMenu(QObject *plugin, const QStringList &texts,
316 QMenu *menu, Member member,
317 QActionGroup *actionGroup)
318{
319 for (const QString &text : texts) {
320 auto action = new QAction(text, plugin);
321 connect(sender: action, signal: &QAction::triggered, receiver: this, slot: member);
322 menu->addAction(action);
323
324 if (actionGroup) {
325 action->setCheckable(true);
326 actionGroup->addAction(a: action);
327 }
328 }
329}
330

source code of qtbase/examples/widgets/tools/plugandpaint/app/mainwindow.cpp