Unity 8
windowscreenshotprovider.cpp
1 /*
2  * Copyright (C) 2015 Canonical, Ltd.
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License as published by
6  * the Free Software Foundation; version 3.
7  *
8  * This program is distributed in the hope that it will be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11  * GNU General Public License for more details.
12  *
13  * You should have received a copy of the GNU General Public License
14  * along with this program. If not, see <http://www.gnu.org/licenses/>.
15  */
16 
17 #include "windowscreenshotprovider.h"
18 
19 #include <QGuiApplication>
20 #include <QQuickWindow>
21 
22 WindowScreenshotProvider::WindowScreenshotProvider()
23  : QQuickImageProvider(QQmlImageProviderBase::Image, 0)
24 {
25 }
26 
27 // A very simple implementation where we assume that there's only one window and that it's a
28 // QQuickWindow. Thus the id parameter is irrelevant.
29 //
30 // Idea: Make the id contain the objectName of the QQuickWindow once we care about a multi-display
31 // compositor?
32 // Strictly speaking that could be the actual QWindow::winId(), but that's mostly a
33 // meaningless arbitrary number.
34 QImage WindowScreenshotProvider::requestImage(const QString &id, QSize *size, const QSize &requestedSize)
35 {
36  Q_UNUSED(id);
37  Q_UNUSED(requestedSize);
38 
39  QWindowList windows = QGuiApplication::topLevelWindows();
40 
41  if (windows.count() != 1) {
42  size->rwidth() = 0;
43  size->rheight() = 0;
44  return QImage();
45  }
46 
47  QQuickWindow *quickWindow = qobject_cast<QQuickWindow *>(windows[0]);
48 
49  if (!quickWindow) {
50  size->rwidth() = 0;
51  size->rheight() = 0;
52  return QImage();
53  }
54 
55  QImage image = quickWindow->grabWindow();
56  size->rwidth() = image.width();
57  size->rheight() = image.height();
58  return image;
59 }