backends/virtual: Drop KWIN_WAYLAND_VIRTUAL_SCREENSHOTS

Virtual backend is used primarily by tests, there are plans to use it
for virtual outputs too. But in either case we don't need screenshots.

I also can't imagine how it can be useful as a debugging tool. It's more
convenient to spin a windowed kwin instance.

The main motivation behind this change is to get rid of custom code in
virtual output layers and simplify it a bit more.

src/backends/virtual/virtual_backend.cpp

@@ -11,8 +11,6 @@
 #include "virtual_egl_backend.h"
 #include "virtual_output.h"
 #include "virtual_qpainter_backend.h"
-// Qt
-#include <QTemporaryDir>
 
 namespace KWin
 {
@@ -20,15 +18,6 @@ namespace KWin
 VirtualBackend::VirtualBackend(QObject *parent)
     : OutputBackend(parent)
 {
-    if (qEnvironmentVariableIsSet("KWIN_WAYLAND_VIRTUAL_SCREENSHOTS")) {
-        m_screenshotDir.reset(new QTemporaryDir);
-        if (!m_screenshotDir->isValid()) {
-            m_screenshotDir.reset();
-        }
-        if (m_screenshotDir) {
-            qDebug() << "Screenshots saved to: " << m_screenshotDir->path();
-        }
-    }
 }
 
 VirtualBackend::~VirtualBackend()
@@ -43,14 +32,6 @@ bool VirtualBackend::initialize()
     return true;
 }
 
-QString VirtualBackend::screenshotDirPath() const
-{
-    if (!m_screenshotDir) {
-        return QString();
-    }
-    return m_screenshotDir->path();
-}
-
 std::unique_ptr<QPainterBackend> VirtualBackend::createQPainterBackend()
 {
     return std::make_unique<VirtualQPainterBackend>(this);

src/backends/virtual/virtual_backend.h

@@ -15,8 +15,6 @@
 #include <QObject>
 #include <QRect>
 
-class QTemporaryDir;
-
 namespace KWin
 {
 class VirtualBackend;
@@ -32,12 +30,6 @@ public:
 
     bool initialize() override;
 
-    bool saveFrames() const
-    {
-        return m_screenshotDir != nullptr;
-    }
-    QString screenshotDirPath() const;
-
     std::unique_ptr<QPainterBackend> createQPainterBackend() override;
     std::unique_ptr<OpenGLBackend> createOpenGLBackend() override;
 
@@ -59,7 +51,6 @@ private:
     VirtualOutput *createOutput(const QPoint &position, const QSize &size, qreal scale);
 
     QVector<VirtualOutput *> m_outputs;
-    std::unique_ptr<QTemporaryDir> m_screenshotDir;
 };
 
 } // namespace KWin

src/backends/virtual/virtual_egl_backend.cpp

@@ -201,11 +201,6 @@ void VirtualEglBackend::present(Output *output)
     glFlush();
 
     static_cast<VirtualOutput *>(output)->vsyncMonitor()->arm();
-
-    if (m_backend->saveFrames()) {
-        const std::unique_ptr<VirtualEglLayer> &layer = m_outputs[output];
-        layer->texture()->toImage().save(QStringLiteral("%1/%2-%3.png").arg(m_backend->screenshotDirPath(), output->name(), QString::number(m_frameCounter++)));
-    }
 }
 
 } // namespace

src/backends/virtual/virtual_egl_backend.h

@@ -61,7 +61,6 @@ private:
     void removeOutput(Output *output);
 
     VirtualBackend *m_backend;
-    int m_frameCounter = 0;
     std::map<Output *, std::unique_ptr<VirtualEglLayer>> m_outputs;
 };
 

src/backends/virtual/virtual_qpainter_backend.cpp

@@ -42,8 +42,6 @@ QImage *VirtualQPainterLayer::image()
 }
 
 VirtualQPainterBackend::VirtualQPainterBackend(VirtualBackend *backend)
-    : QPainterBackend()
-    , m_backend(backend)
 {
     connect(backend, &VirtualBackend::outputAdded, this, &VirtualQPainterBackend::addOutput);
     connect(backend, &VirtualBackend::outputRemoved, this, &VirtualQPainterBackend::removeOutput);
@@ -69,10 +67,6 @@ void VirtualQPainterBackend::removeOutput(Output *output)
 void VirtualQPainterBackend::present(Output *output)
 {
     static_cast<VirtualOutput *>(output)->vsyncMonitor()->arm();
-
-    if (m_backend->saveFrames()) {
-        m_outputs[output]->image()->save(QStringLiteral("%1/%2-%3.png").arg(m_backend->screenshotDirPath(), output->name(), QString::number(m_frameCounter++)));
-    }
 }
 
 VirtualQPainterLayer *VirtualQPainterBackend::primaryLayer(Output *output)

src/backends/virtual/virtual_qpainter_backend.h

@@ -50,8 +50,6 @@ private:
     void removeOutput(Output *output);
 
     std::map<Output *, std::unique_ptr<VirtualQPainterLayer>> m_outputs;
-    VirtualBackend *m_backend;
-    int m_frameCounter = 0;
 };
 
 } // namespace KWin