Move ScreenPreviewWidget from kworspace libs to KWin's screenedges kcm

The ScreenPreviewWidget doesn't make much sense any more for the general
useage as it's not QML based and thus not suited for any usage in Plasma.
This means that features like previewing the Plasma wallpaper cannot
work any more.

The Widget is only used in a few KCMs (KDM, Screensavers, Screenedges).
Currently we expect that KDM and legacy X Screensavers won't make it into
the next release, it makes sense to just move the widget to screenedges
where it's still useful.

This change has been discussed with notmart.

kcmkwin/kwinscreenedges/CMakeLists.txt

@@ -4,6 +4,7 @@ set(
     kcm_kwinscreenedges_PART_SRCS
     main.cpp
     monitor.cpp
+    screenpreviewwidget.cpp
     )
 kde4_add_ui_files( kcm_kwinscreenedges_PART_SRCS main.ui )
 kde4_add_plugin( kcm_kwinscreenedges ${kcm_kwinscreenedges_PART_SRCS} )

kcmkwin/kwinscreenedges/screenpreviewwidget.cpp

@@ -0,0 +1,197 @@
+/* This file is part of the KDE libraries
+
+   Copyright (C) 2009 Marco Martin <notmart@gmail.com>
+
+   This library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public
+   License as published by the Free Software Foundation; either
+   version 2 of the License, or (at your option) any later version.
+
+   This library 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
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public License
+   along with this library; see the file COPYING.LIB.  If not, write to
+   the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+   Boston, MA 02110-1301, USA.
+*/
+
+#include "screenpreviewwidget.h"
+
+#include <QResizeEvent>
+#include <QPaintEvent>
+#include <QPainter>
+
+#include <KDebug>
+
+#include "Plasma/FrameSvg"
+#include "Plasma/Wallpaper"
+
+
+class ScreenPreviewWidgetPrivate
+{
+public:
+    ScreenPreviewWidgetPrivate(ScreenPreviewWidget *screen)
+          : q(screen),
+            wallpaper(0),
+            ratio(1)
+    {}
+
+    ~ScreenPreviewWidgetPrivate()
+    {}
+
+    void updateRect(const QRectF& rect)
+    {
+        q->update(rect.toRect());
+    }
+
+    void updateScreenGraphics()
+    {
+        int bottomElements = screenGraphics->elementSize("base").height() + screenGraphics->marginSize(Plasma::BottomMargin);
+        QRect bounds(QPoint(0,0), QSize(q->size().width(), q->height() - bottomElements));
+
+        QSize monitorSize(q->size().width(), q->size().width()/ratio);
+        monitorSize.scale(bounds.size(), Qt::KeepAspectRatio);
+
+        if (monitorSize.isEmpty()) {
+            return;
+        }
+
+        monitorRect = QRect(QPoint(0,0), monitorSize);
+        monitorRect.moveCenter(bounds.center());
+
+        screenGraphics->resizeFrame(monitorRect.size());
+
+        previewRect = screenGraphics->contentsRect().toRect();
+        previewRect.moveCenter(bounds.center());
+
+        if (wallpaper && !previewRect.isEmpty()) {
+            wallpaper->setBoundingRect(previewRect);
+        }
+    }
+
+    void wallpaperDeleted()
+    {
+        wallpaper = 0;
+    }
+
+    ScreenPreviewWidget *q;
+    Plasma::Wallpaper* wallpaper;
+    Plasma::FrameSvg *screenGraphics;
+    QPixmap preview;
+    QRect monitorRect;
+    qreal ratio;
+    QRect previewRect;
+};
+
+ScreenPreviewWidget::ScreenPreviewWidget(QWidget *parent)
+    : QWidget(parent),
+      d(new ScreenPreviewWidgetPrivate(this))
+{
+    d->screenGraphics = new Plasma::FrameSvg(this);
+    d->screenGraphics->setImagePath("widgets/monitor");
+    d->updateScreenGraphics();
+}
+
+ScreenPreviewWidget::~ScreenPreviewWidget()
+{
+   delete d;
+}
+
+void ScreenPreviewWidget::setPreview(const QPixmap &preview)
+{
+    d->preview = preview;
+
+    if (d->wallpaper) {
+        disconnect(d->wallpaper, 0, this, 0);
+        d->wallpaper = 0;
+    }
+    update();
+}
+
+const QPixmap ScreenPreviewWidget::preview() const
+{
+    return d->preview;
+}
+
+void ScreenPreviewWidget::setPreview(Plasma::Wallpaper* wallpaper)
+{
+    d->preview = QPixmap();
+
+    if (d->wallpaper) {
+        disconnect(d->wallpaper, 0, this, 0);
+    }
+
+    d->wallpaper = wallpaper;
+
+    if (d->wallpaper) {
+        connect(d->wallpaper, SIGNAL(update(QRectF)), this, SLOT(updateRect(QRectF)));
+        connect(d->wallpaper, SIGNAL(destroyed(QObject*)), this, SLOT(wallpaperDeleted()));
+        d->updateScreenGraphics();
+    }
+
+    update(d->previewRect);
+}
+
+void ScreenPreviewWidget::setRatio(const qreal ratio)
+{
+    d->ratio = ratio;
+    d->updateScreenGraphics();
+}
+
+qreal ScreenPreviewWidget::ratio() const
+{
+    return d->ratio;
+}
+
+QRect ScreenPreviewWidget::previewRect() const
+{
+    return d->previewRect;
+}
+
+void ScreenPreviewWidget::resizeEvent(QResizeEvent *e)
+{
+    Q_UNUSED(e)
+    d->updateScreenGraphics();
+}
+
+void ScreenPreviewWidget::paintEvent(QPaintEvent *event)
+{
+    if (d->monitorRect.size().isEmpty()) {
+        return;
+    }
+
+    QPainter painter(this);
+    QPoint standPosition(d->monitorRect.center().x() - d->screenGraphics->elementSize("base").width()/2, d->previewRect.bottom());
+
+    d->screenGraphics->paint(&painter, QRect(standPosition, d->screenGraphics->elementSize("base")), "base");
+    d->screenGraphics->paintFrame(&painter, d->monitorRect.topLeft());
+
+    painter.save();
+    if (d->wallpaper) {
+        d->wallpaper->paint(&painter, event->rect().intersected(d->previewRect));
+    } else if (!d->preview.isNull()) {
+        painter.setRenderHint(QPainter::SmoothPixmapTransform);
+        painter.drawPixmap(d->previewRect, d->preview, d->preview.rect());
+    }
+    painter.restore();
+
+    d->screenGraphics->paint(&painter, d->previewRect, "glass");
+}
+
+void ScreenPreviewWidget::dropEvent(QDropEvent *e)
+{
+    if (!KUrl::List::canDecode(e->mimeData()))
+        return;
+
+    const KUrl::List uris(KUrl::List::fromMimeData(e->mimeData()));
+    if (!uris.isEmpty()) {
+        // TODO: Download remote file
+        if (uris.first().isLocalFile())
+           emit imageDropped(uris.first().path());
+    }
+}
+
+#include "screenpreviewwidget.moc"

kcmkwin/kwinscreenedges/screenpreviewwidget.h

@@ -0,0 +1,67 @@
+/* This file is part of the KDE libraries
+
+   Copyright (C) 2009 Marco Martin <notmart@gmail.com>
+
+   This library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public
+   License as published by the Free Software Foundation; either
+   version 2 of the License, or (at your option) any later version.
+
+   This library 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
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public License
+   along with this library; see the file COPYING.LIB.  If not, write to
+   the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+   Boston, MA 02110-1301, USA.
+*/
+
+#ifndef SCREENPREVIEWWIDGET_H
+#define SCREENPREVIEWWIDGET_H
+
+#include <QWidget>
+
+class Wallpaper;
+
+class ScreenPreviewWidgetPrivate;
+
+namespace Plasma
+{
+    class Wallpaper;
+}
+
+class ScreenPreviewWidget : public QWidget
+{
+    Q_OBJECT
+
+public:
+    ScreenPreviewWidget(QWidget *parent);
+    ~ScreenPreviewWidget();
+
+    void setPreview(const QPixmap &preview);
+    void setPreview(Plasma::Wallpaper* wallpaper);
+    const QPixmap preview() const;
+    void setRatio(const qreal ratio);
+    qreal ratio() const;
+
+    QRect previewRect() const;
+
+protected:
+    void resizeEvent(QResizeEvent *event);
+    void paintEvent(QPaintEvent *event);
+    virtual void dropEvent(QDropEvent *event);
+
+Q_SIGNALS:
+    void imageDropped(const QString &);
+
+private:
+    ScreenPreviewWidgetPrivate *const d;
+
+    Q_PRIVATE_SLOT(d, void updateRect(const QRectF& rect))
+    Q_PRIVATE_SLOT(d, void wallpaperDeleted())
+};
+
+
+#endif