comparison panner.cpp @ 45:4286836bb3c9

* Some more work on graph layout; ensure LANG is set for parseable UTF8 output when running Hg

+/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*- vi:set ts=8 sts=4 sw=4: */
+
+/*
+    Rosegarden
+    A MIDI and audio sequencer and musical notation editor.
+    Copyright 2000-2010 the Rosegarden development team.
+ 
+    Other copyrights also apply to some parts of this work.  Please
+    see the AUTHORS file and individual file headers for details.
+ 
+    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.  See the file
+    COPYING included with this distribution for more information.
+*/
+
+#include "panner.h"
+#include "panned.h"
+
+#include <QPolygon>
+#include <QMouseEvent>
+#include <QColor>
+
+#include <iostream>
+
+class PannerScene : public QGraphicsScene
+{
+public:
+    friend class Panner;
+};
+
+Panner::Panner() :
+    m_clicked(false)
+{
+    setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
+    setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
+    setOptimizationFlags(QGraphicsView::DontSavePainterState);
+    setMouseTracking(true);
+    setInteractive(false);
+}
+
+void
+Panner::setScene(QGraphicsScene *s)
+{
+    if (scene()) {
+        disconnect(scene(), SIGNAL(sceneRectChanged(const QRectF &)),
+                   this, SLOT(slotSceneRectChanged(const QRectF &)));
+    }
+    QGraphicsView::setScene(s);
+    if (scene()) fitInView(sceneRect(), Qt::IgnoreAspectRatio);
+    m_cache = QPixmap();
+    connect(scene(), SIGNAL(sceneRectChanged(const QRectF &)),
+            this, SLOT(slotSceneRectChanged(const QRectF &)));
+}
+
+void
+Panner::connectToPanned(Panned *p)
+{
+    connect(p, SIGNAL(pannedRectChanged(QRectF)),
+            this, SLOT(slotSetPannedRect(QRectF)));
+
+    connect(this, SIGNAL(pannedRectChanged(QRectF)),
+            p, SLOT(slotSetPannedRect(QRectF)));
+}
+
+void
+Panner::slotSetPannedRect(QRectF rect) 
+{
+    m_pannedRect = rect;
+    viewport()->update();
+}
+
+void
+Panner::resizeEvent(QResizeEvent *)
+{
+    if (scene()) fitInView(sceneRect(), Qt::IgnoreAspectRatio);
+    m_cache = QPixmap();
+}
+
+void
+Panner::slotSceneRectChanged(const QRectF &newRect)
+{
+    if (!scene()) return; // spurious
+    fitInView(newRect, Qt::IgnoreAspectRatio);
+    m_cache = QPixmap();
+    viewport()->update();
+}
+
+void
+Panner::paintEvent(QPaintEvent *e)
+{
+    QPaintEvent *e2 = new QPaintEvent(e->region().boundingRect());
+    QGraphicsView::paintEvent(e2);
+
+    QPainter paint;
+    paint.begin(viewport());
+    paint.setClipRegion(e->region());
+
+    QPainterPath path;
+    path.addRect(rect());
+    path.addPolygon(mapFromScene(m_pannedRect));
+
+    QColor c(QColor::fromHsv(211, 194, 238));
+    c.setAlpha(80);
+    paint.setPen(Qt::NoPen);
+    paint.setBrush(c);
+    paint.drawPath(path);
+
+    paint.setBrush(Qt::NoBrush);
+    paint.setPen(QPen(QColor::fromHsv(211, 194, 238), 0));
+    paint.drawConvexPolygon(mapFromScene(m_pannedRect));
+
+    paint.end();
+
+    emit pannerChanged(m_pannedRect);
+}
+
+void
+Panner::updateScene(const QList<QRectF> &rects)
+{
+    if (!m_cache.isNull()) m_cache = QPixmap();
+    QGraphicsView::updateScene(rects);
+}
+
+void
+Panner::drawItems(QPainter *painter, int numItems,
+                  QGraphicsItem *items[],
+                  const QStyleOptionGraphicsItem options[])
+{
+    if (m_cache.size() != viewport()->size()) {
+
+        QGraphicsScene *s = scene();
+        if (!s) return;
+        PannerScene *ps = static_cast<PannerScene *>(s);
+
+        m_cache = QPixmap(viewport()->size());
+        m_cache.fill(Qt::transparent);
+        QPainter cachePainter;
+        cachePainter.begin(&m_cache);
+        cachePainter.setTransform(viewportTransform());
+        ps->drawItems(&cachePainter, numItems, items, options);
+        cachePainter.end();
+    }
+
+    painter->save();
+    painter->setTransform(QTransform());
+    painter->drawPixmap(0, 0, m_cache);
+    painter->restore();
+}
+ 
+void
+Panner::mousePressEvent(QMouseEvent *e)
+{
+    if (e->button() != Qt::LeftButton) {
+        QGraphicsView::mouseDoubleClickEvent(e);
+        return;
+    }
+    m_clicked = true;
+    m_clickedRect = m_pannedRect;
+    m_clickedPoint = e->pos();
+}
+
+void
+Panner::mouseDoubleClickEvent(QMouseEvent *e)
+{
+    if (e->button() != Qt::LeftButton) {
+        QGraphicsView::mouseDoubleClickEvent(e);
+        return;
+    }
+
+    moveTo(e->pos());
+}
+
+void
+Panner::mouseMoveEvent(QMouseEvent *e)
+{
+    if (!m_clicked) return;
+    QPointF cp = mapToScene(m_clickedPoint);
+    QPointF mp = mapToScene(e->pos());
+    QPointF delta = mp - cp;
+    QRectF nr = m_clickedRect;
+    nr.translate(delta);
+    slotSetPannedRect(nr);
+    emit pannedRectChanged(m_pannedRect);
+    viewport()->update();
+}
+
+void
+Panner::mouseReleaseEvent(QMouseEvent *e)
+{
+    if (e->button() != Qt::LeftButton) {
+        QGraphicsView::mouseDoubleClickEvent(e);
+        return;
+    }
+
+    if (m_clicked) {
+        mouseMoveEvent(e);
+    }
+
+    m_clicked = false;
+    viewport()->update();
+}
+
+void
+Panner::wheelEvent(QWheelEvent *e)
+{
+    if (e->delta() > 0) {
+        emit zoomOut();
+    } else {
+        emit zoomIn();
+    }
+}
+
+void
+Panner::moveTo(QPoint p)
+{
+    QPointF sp = mapToScene(p);
+    QRectF nr = m_pannedRect;
+    double d = sp.x() - nr.center().x();
+    nr.translate(d, 0);
+    slotSetPannedRect(nr);
+    emit pannedRectChanged(m_pannedRect);
+    viewport()->update();
+}
+