kwin/effects/screenshot/screenshot.h
Martin Gräßlin fbab204968 [effects] Add a screenshot dbus method which takes a file descriptor
Summary:
The idea behind this mode is to support applications like spectacle
(see T4458). The calling application passes a file descriptor (created
through e.g. a pipe) and the screenshot effect writes the captured image
into that fd.

The advantage over the existing variant which writes to a file in the
/tmp directory is that this is peer-to-peer between the requesting
application and KWin. No other application can get to that image.

The change also includes setting SIGPIPE to ignore. It showed that when
the reading side already cancelled the read prior to KWin writing out
the image we get a SIGPIPE which results in application termination,
which is not what we want in case of a Wayland compositor. The sigpipe
can be ignored as Qt (and libpng) handles that error just fine at
runtime.

Reviewers: #kwin, #plasma_on_wayland

Subscribers: plasma-devel, kwin

Tags: #plasma_on_wayland, #kwin

Differential Revision: https://phabricator.kde.org/D3412
2016-11-22 07:17:57 +01:00

143 lines
5.4 KiB
C++

/********************************************************************
KWin - the KDE window manager
This file is part of the KDE project.
Copyright (C) 2010 Martin Gräßlin <mgraesslin@kde.org>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*********************************************************************/
#ifndef KWIN_SCREENSHOT_H
#define KWIN_SCREENSHOT_H
#include <kwineffects.h>
#include <QDBusContext>
#include <QDBusConnection>
#include <QDBusMessage>
#include <QDBusUnixFileDescriptor>
#include <QObject>
#include <QImage>
namespace KWin
{
class ScreenShotEffect : public Effect, protected QDBusContext
{
Q_OBJECT
Q_CLASSINFO("D-Bus Interface", "org.kde.kwin.Screenshot")
public:
enum ScreenShotType {
INCLUDE_DECORATION = 1 << 0,
INCLUDE_CURSOR = 1 << 1
};
ScreenShotEffect();
virtual ~ScreenShotEffect();
void paintScreen(int mask, QRegion region, ScreenPaintData &data) override;
virtual void postPaintScreen();
virtual bool isActive() const;
int requestedEffectChainPosition() const override {
return 50;
}
static bool supported();
static void convertFromGLImage(QImage &img, int w, int h);
public Q_SLOTS:
Q_SCRIPTABLE void screenshotForWindow(qulonglong winid, int mask = 0);
/**
* Starts an interactive window screenshot session. The user can select a window to
* screenshot.
*
* Once the window is selected the screenshot is saved into a file and the path gets
* returned to the DBus peer.
*
* @param mask The mask for what to include in the screenshot
**/
Q_SCRIPTABLE QString interactive(int mask = 0);
/**
* Starts an interactive window screenshot session. The user can select a window to
* screenshot.
*
* Once the window is selected the screenshot is saved into the @p fd passed to the
* method. It is intended to be used with a pipe, so that the invoking side can just
* read from the pipe. The image gets written into the fd using a QDataStream.
*
* @param fd File descriptor into which the screenshot should be saved
* @param mask The mask for what to include in the screenshot
**/
Q_SCRIPTABLE void interactive(QDBusUnixFileDescriptor fd, int mask = 0);
Q_SCRIPTABLE void screenshotWindowUnderCursor(int mask = 0);
/**
* Saves a screenshot of all screen into a file and returns the path to the file.
* Functionality requires hardware support, if not available a null string is returned.
* @param captureCursor Whether to include the cursor in the image
* @returns Path to stored screenshot, or null string in failure case.
**/
Q_SCRIPTABLE QString screenshotFullscreen(bool captureCursor = false);
/**
* Saves a screenshot of the screen identified by @p screen into a file and returns the path to the file.
* Functionality requires hardware support, if not available a null string is returned.
* @param screen Number of screen as numbered by QDesktopWidget
* @param captureCursor Whether to include the cursor in the image
* @returns Path to stored screenshot, or null string in failure case.
**/
Q_SCRIPTABLE QString screenshotScreen(int screen, bool captureCursor = false);
/**
* Saves a screenshot of the selected geometry into a file and returns the path to the file.
* Functionality requires hardware support, if not available a null string is returned.
* @param x Left upper x coord of region
* @param y Left upper y coord of region
* @param width Width of the region to screenshot
* @param height Height of the region to screenshot
* @param captureCursor Whether to include the cursor in the image
* @returns Path to stored screenshot, or null string in failure case.
**/
Q_SCRIPTABLE QString screenshotArea(int x, int y, int width, int height, bool captureCursor = false);
Q_SIGNALS:
Q_SCRIPTABLE void screenshotCreated(qulonglong handle);
private Q_SLOTS:
void windowClosed( KWin::EffectWindow* w );
private:
void grabPointerImage(QImage& snapshot, int offsetx, int offsety);
QImage blitScreenshot(const QRect &geometry);
QString saveTempImage(const QImage &img);
void sendReplyImage(const QImage &img);
void showInfoMessage();
void hideInfoMessage();
EffectWindow *m_scheduledScreenshot;
ScreenShotType m_type;
QRect m_scheduledGeometry;
QDBusConnection m_replyConnection;
QDBusMessage m_replyMessage;
QRect m_cachedOutputGeometry;
QImage m_multipleOutputsImage;
QRegion m_multipleOutputsRendered;
bool m_captureCursor = false;
enum class WindowMode {
NoCapture,
Xpixmap,
File,
FileDescriptor
};
WindowMode m_windowMode = WindowMode::NoCapture;
int m_fd = -1;
QScopedPointer<EffectFrame> m_infoFrame;
};
} // namespace
#endif // KWIN_SCREENSHOT_H