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39
40#include "qsplashscreen.h"
41
42#include "qapplication.h"
43#include "qdesktopwidget.h"
44#include <private/qdesktopwidget_p.h>
45#include "qpainter.h"
46#include "qpixmap.h"
47#include "qtextdocument.h"
48#include "qtextcursor.h"
49#include <QtGui/qscreen.h>
50#include <QtGui/qwindow.h>
51#include <QtCore/qdebug.h>
52#include <QtCore/qelapsedtimer.h>
53#include <private/qwidget_p.h>
54
55#ifdef Q_OS_WIN
56# include <QtCore/qt_windows.h>
57#else
58# include <time.h>
59#endif
60
61QT_BEGIN_NAMESPACE
62
63class QSplashScreenPrivate : public QWidgetPrivate
64{
65 Q_DECLARE_PUBLIC(QSplashScreen)
66public:
67 QPixmap pixmap;
68 QString currStatus;
69 QColor currColor;
70 int currAlign;
71
72 inline QSplashScreenPrivate();
73
74 void setPixmap(const QPixmap &p, const QScreen *screen = nullptr);
75
76 static const QScreen *screenFor(const QWidget *w);
77};
78
79/*!
80 \class QSplashScreen
81 \brief The QSplashScreen widget provides a splash screen that can
82 be shown during application startup.
83
84 \inmodule QtWidgets
85
86 A splash screen is a widget that is usually displayed when an
87 application is being started. Splash screens are often used for
88 applications that have long start up times (e.g. database or
89 networking applications that take time to establish connections) to
90 provide the user with feedback that the application is loading.
91
92 The splash screen appears in the center of the screen. It may be
93 useful to add the Qt::WindowStaysOnTopHint to the splash widget's
94 window flags if you want to keep it above all the other windows on
95 the desktop.
96
97 Some X11 window managers do not support the "stays on top" flag. A
98 solution is to set up a timer that periodically calls raise() on
99 the splash screen to simulate the "stays on top" effect.
100
101 The most common usage is to show a splash screen before the main
102 widget is displayed on the screen. This is illustrated in the
103 following code snippet in which a splash screen is displayed and
104 some initialization tasks are performed before the application's
105 main window is shown:
106
107 \snippet qsplashscreen/main.cpp 0
108 \dots
109 \snippet qsplashscreen/main.cpp 1
110
111 The user can hide the splash screen by clicking on it with the
112 mouse. Since the splash screen is typically displayed before the
113 event loop has started running, it is necessary to periodically
114 call QCoreApplication::processEvents() to receive the mouse clicks.
115
116 It is sometimes useful to update the splash screen with messages,
117 for example, announcing connections established or modules loaded
118 as the application starts up:
119
120 \snippet code/src_gui_widgets_qsplashscreen.cpp 0
121
122 QSplashScreen supports this with the showMessage() function. If you
123 wish to do your own drawing you can get a pointer to the pixmap
124 used in the splash screen with pixmap(). Alternatively, you can
125 subclass QSplashScreen and reimplement drawContents().
126
127 In case of having multiple screens, it is also possible to show the
128 splash screen on a different screen than the primary one. For example:
129
130 \snippet qsplashscreen/main.cpp 2
131*/
132
133/*!
134 Construct a splash screen that will display the \a pixmap.
135
136 There should be no need to set the widget flags, \a f, except
137 perhaps Qt::WindowStaysOnTopHint.
138*/
139QSplashScreen::QSplashScreen(const QPixmap &pixmap, Qt::WindowFlags f)
140 : QWidget(*(new QSplashScreenPrivate()), nullptr, Qt::SplashScreen | Qt::FramelessWindowHint | f)
141{
142 setPixmap(pixmap); // Does an implicit repaint
143}
144
145/*!
146 \overload
147 \since 5.15
148
149 This function allows you to specify the screen for your splashscreen. The
150 typical use for this constructor is if you have multiple screens and
151 prefer to have the splash screen on a different screen than your primary
152 one. In that case pass the proper \a screen.
153*/
154QSplashScreen::QSplashScreen(QScreen *screen, const QPixmap &pixmap, Qt::WindowFlags f)
155 : QWidget(*(new QSplashScreenPrivate()), nullptr, Qt::SplashScreen | Qt::FramelessWindowHint | f)
156{
157 d_func()->setPixmap(p: pixmap, screen);
158}
159
160#if QT_DEPRECATED_SINCE(5, 15)
161/*!
162 \overload
163 \obsolete Use the constructor taking a \c {QScreen *} instead
164
165 This function allows you to specify a parent for your splashscreen. The
166 typical use for this constructor is if you have a multiple screens and
167 prefer to have the splash screen on a different screen than your primary
168 one. In that case pass the proper desktop() as the \a parent.
169*/
170QSplashScreen::QSplashScreen(QWidget *parent, const QPixmap &pixmap, Qt::WindowFlags f)
171 : QWidget(*new QSplashScreenPrivate, parent, Qt::SplashScreen | Qt::FramelessWindowHint | f)
172{
173 // Does an implicit repaint. Explicitly pass parent as QObject::parent()
174 // is still 0 here due to QWidget's special handling.
175 d_func()->setPixmap(p: pixmap, screen: QSplashScreenPrivate::screenFor(w: parent));
176}
177#endif
178
179/*!
180 Destructor.
181*/
182QSplashScreen::~QSplashScreen()
183{
184}
185
186/*!
187 \reimp
188*/
189void QSplashScreen::mousePressEvent(QMouseEvent *)
190{
191 hide();
192}
193
194/*!
195 This overrides QWidget::repaint(). It differs from the standard repaint
196 function in that it also calls QCoreApplication::processEvents() to ensure
197 the updates are displayed, even when there is no event loop present.
198*/
199void QSplashScreen::repaint()
200{
201 QWidget::repaint();
202 QCoreApplication::processEvents();
203}
204
205/*!
206 \fn QSplashScreen::messageChanged(const QString &message)
207
208 This signal is emitted when the message on the splash screen
209 changes. \a message is the new message and is a null-string
210 when the message has been removed.
211
212 \sa showMessage(), clearMessage()
213*/
214
215
216
217/*!
218 Draws the \a message text onto the splash screen with color \a
219 color and aligns the text according to the flags in \a alignment.
220 This function calls repaint() to make sure the splash screen is
221 repainted immediately. As a result the message is kept up
222 to date with what your application is doing (e.g. loading files).
223
224 \sa Qt::Alignment, clearMessage(), message()
225*/
226void QSplashScreen::showMessage(const QString &message, int alignment,
227 const QColor &color)
228{
229 Q_D(QSplashScreen);
230 d->currStatus = message;
231 d->currAlign = alignment;
232 d->currColor = color;
233 emit messageChanged(message: d->currStatus);
234 repaint();
235}
236
237/*!
238 \since 5.2
239
240 Returns the message that is currently displayed on the splash screen.
241
242 \sa showMessage(), clearMessage()
243*/
244
245QString QSplashScreen::message() const
246{
247 Q_D(const QSplashScreen);
248 return d->currStatus;
249}
250
251/*!
252 Removes the message being displayed on the splash screen
253
254 \sa showMessage()
255 */
256void QSplashScreen::clearMessage()
257{
258 d_func()->currStatus.clear();
259 emit messageChanged(message: d_func()->currStatus);
260 repaint();
261}
262
263// A copy of Qt Test's qWaitForWindowExposed() and qSleep().
264inline static bool waitForWindowExposed(QWindow *window, int timeout = 1000)
265{
266 enum { TimeOutMs = 10 };
267 QElapsedTimer timer;
268 timer.start();
269 while (!window->isExposed()) {
270 const int remaining = timeout - int(timer.elapsed());
271 if (remaining <= 0)
272 break;
273 QCoreApplication::processEvents(flags: QEventLoop::AllEvents, maxtime: remaining);
274 QCoreApplication::sendPostedEvents(receiver: nullptr, event_type: QEvent::DeferredDelete);
275#if defined(Q_OS_WINRT)
276 WaitForSingleObjectEx(GetCurrentThread(), TimeOutMs, false);
277#elif defined(Q_OS_WIN)
278 Sleep(uint(TimeOutMs));
279#else
280 struct timespec ts = { .tv_sec: TimeOutMs / 1000, .tv_nsec: (TimeOutMs % 1000) * 1000 * 1000 };
281 nanosleep(requested_time: &ts, remaining: nullptr);
282#endif
283 }
284 return window->isExposed();
285}
286
287/*!
288 Makes the splash screen wait until the widget \a mainWin is displayed
289 before calling close() on itself.
290*/
291
292void QSplashScreen::finish(QWidget *mainWin)
293{
294 if (mainWin) {
295 if (!mainWin->windowHandle())
296 mainWin->createWinId();
297 waitForWindowExposed(window: mainWin->windowHandle());
298 }
299 close();
300}
301
302/*!
303 Sets the pixmap that will be used as the splash screen's image to
304 \a pixmap.
305*/
306void QSplashScreen::setPixmap(const QPixmap &pixmap)
307{
308 d_func()->setPixmap(p: pixmap, screen: QSplashScreenPrivate::screenFor(w: this));
309}
310
311// In setPixmap(), resize and try to position on a screen according to:
312// 1) If the screen for the given widget is available, use that
313// 2) If a QDesktopScreenWidget is found in the parent hierarchy, use that (see docs on
314// QSplashScreen(QWidget *, QPixmap).
315// 3) If a widget with associated QWindow is found, use that
316// 4) When nothing can be found, try to center it over the cursor
317
318#if QT_DEPRECATED_SINCE(5, 15)
319static inline int screenNumberOf(const QDesktopScreenWidget *dsw)
320{
321 auto desktopWidgetPrivate =
322 static_cast<QDesktopWidgetPrivate *>(qt_widget_private(widget: QApplication::desktop()));
323 return desktopWidgetPrivate->screens.indexOf(t: const_cast<QDesktopScreenWidget *>(dsw));
324}
325#endif
326
327const QScreen *QSplashScreenPrivate::screenFor(const QWidget *w)
328{
329 if (w && w->screen())
330 return w->screen();
331
332 for (const QWidget *p = w; p !=nullptr ; p = p->parentWidget()) {
333#if QT_DEPRECATED_SINCE(5, 15)
334 if (auto dsw = qobject_cast<const QDesktopScreenWidget *>(object: p))
335 return QGuiApplication::screens().value(i: screenNumberOf(dsw));
336#endif
337 if (QWindow *window = p->windowHandle())
338 return window->screen();
339 }
340
341#if QT_CONFIG(cursor)
342 // Note: We could rely on QPlatformWindow::initialGeometry() to center it
343 // over the cursor, but not all platforms (namely Android) use that.
344 if (QGuiApplication::screens().size() > 1) {
345 if (auto screenAtCursor = QGuiApplication::screenAt(point: QCursor::pos()))
346 return screenAtCursor;
347 }
348#endif // cursor
349 return QGuiApplication::primaryScreen();
350}
351
352void QSplashScreenPrivate::setPixmap(const QPixmap &p, const QScreen *screen)
353{
354 Q_Q(QSplashScreen);
355
356 pixmap = p;
357 q->setAttribute(Qt::WA_TranslucentBackground, on: pixmap.hasAlpha());
358
359 QRect r(QPoint(), pixmap.size() / pixmap.devicePixelRatio());
360 q->resize(r.size());
361 if (screen)
362 q->move(screen->geometry().center() - r.center());
363 if (q->isVisible())
364 q->repaint();
365}
366
367/*!
368 Returns the pixmap that is used in the splash screen. The image
369 does not have any of the text drawn by showMessage() calls.
370*/
371const QPixmap QSplashScreen::pixmap() const
372{
373 return d_func()->pixmap;
374}
375
376/*!
377 \internal
378*/
379inline QSplashScreenPrivate::QSplashScreenPrivate() : currAlign(Qt::AlignLeft)
380{
381}
382
383/*!
384 Draw the contents of the splash screen using painter \a painter.
385 The default implementation draws the message passed by showMessage().
386 Reimplement this function if you want to do your own drawing on
387 the splash screen.
388*/
389void QSplashScreen::drawContents(QPainter *painter)
390{
391 Q_D(QSplashScreen);
392 painter->setPen(d->currColor);
393 QRect r = rect().adjusted(xp1: 5, yp1: 5, xp2: -5, yp2: -5);
394 if (Qt::mightBeRichText(d->currStatus)) {
395 QTextDocument doc;
396#ifdef QT_NO_TEXTHTMLPARSER
397 doc.setPlainText(d->currStatus);
398#else
399 doc.setHtml(d->currStatus);
400#endif
401 doc.setTextWidth(r.width());
402 QTextCursor cursor(&doc);
403 cursor.select(selection: QTextCursor::Document);
404 QTextBlockFormat fmt;
405 fmt.setAlignment(Qt::Alignment(d->currAlign));
406 fmt.setLayoutDirection(layoutDirection());
407 cursor.mergeBlockFormat(modifier: fmt);
408 const QSizeF txtSize = doc.size();
409 if (d->currAlign & Qt::AlignBottom)
410 r.setTop(r.height() - txtSize.height());
411 else if (d->currAlign & Qt::AlignVCenter)
412 r.setTop(r.height() / 2 - txtSize.height() / 2);
413 painter->save();
414 painter->translate(offset: r.topLeft());
415 doc.drawContents(painter);
416 painter->restore();
417 } else {
418 painter->drawText(r, flags: d->currAlign, text: d->currStatus);
419 }
420}
421
422/*! \reimp */
423bool QSplashScreen::event(QEvent *e)
424{
425 if (e->type() == QEvent::Paint) {
426 Q_D(QSplashScreen);
427 QPainter painter(this);
428 painter.setRenderHints(hints: QPainter::SmoothPixmapTransform);
429 painter.setLayoutDirection(layoutDirection());
430 if (!d->pixmap.isNull())
431 painter.drawPixmap(p: QPoint(), pm: d->pixmap);
432 drawContents(painter: &painter);
433 }
434 return QWidget::event(event: e);
435}
436
437QT_END_NAMESPACE
438
439#include "moc_qsplashscreen.cpp"
440

source code of qtbase/src/widgets/widgets/qsplashscreen.cpp