comparison base/Layer.h @ 0:da6937383da8

initial import

+
+/* -*- c-basic-offset: 4 -*-  vi:set ts=8 sts=4 sw=4: */
+
+/*
+    A waveform viewer and audio annotation editor.
+    Chris Cannam, Queen Mary University of London, 2005
+    
+    This is experimental software.  Not for distribution.
+*/
+
+#ifndef _VIEWER_H_
+#define _VIEWER_H_
+
+#include "PropertyContainer.h"
+
+#include <QObject>
+#include <QRect>
+
+class ZoomConstraint;
+class Model;
+class QPainter;
+class View;
+
+/**
+ * The base class for visual representations of the data found in a
+ * Model.  Layers are expected to be able to draw themselves onto a
+ * View, and may also be editable.
+ */
+
+class Layer : public QObject,
+	      public PropertyContainer
+{
+    Q_OBJECT
+
+public:
+    Layer(View *w);
+    virtual ~Layer();
+
+    virtual const Model *getModel() const = 0;
+    virtual const ZoomConstraint *getZoomConstraint() const { return 0; }
+    virtual void paint(QPainter &, QRect) const = 0;   
+
+    enum VerticalPosition {
+	PositionTop, PositionMiddle, PositionBottom
+    };
+    virtual VerticalPosition getPreferredTimeRulerPosition() const {
+	return PositionMiddle;
+    }
+    virtual VerticalPosition getPreferredFrameCountPosition() const {
+	return PositionBottom;
+    }
+
+    virtual QString getPropertyContainerName() const {
+	return objectName();
+    }
+
+    virtual int getVerticalScaleWidth(QPainter &) const { return 0; }
+    virtual void paintVerticalScale(QPainter &, QRect) const { }
+
+    virtual QRect getFeatureDescriptionRect(QPainter &, QPoint) const {
+	return QRect(0, 0, 0, 0);
+    }
+    virtual void paintLocalFeatureDescription(QPainter &, QRect, QPoint) const {
+    }
+
+    /**
+     * This should return true if the view can safely be scrolled
+     * automatically by the widget (simply copying the existing data
+     * and then refreshing the exposed area) without altering its
+     * meaning.  For the widget as a whole this is usually not
+     * possible because of invariant (non-scrolling) material
+     * displayed over the top, but the widget may be able to optimise
+     * scrolling better if it is known that individual views can be
+     * scrolled safely in this way.
+     */
+    virtual bool isLayerScrollable() const { return true; }
+
+    /**
+     * Return the proportion of background work complete in drawing
+     * this view, as a percentage -- in most cases this will be the
+     * value returned by pointer from a call to the underlying model's
+     * isReady(int *) call.  The widget may choose to show a progress
+     * meter if it finds that this returns < 100 at any given moment.
+     */
+    virtual int getCompletion() const { return 100; }
+
+    virtual void setObjectName(const QString &name);
+
+signals:
+    void modelChanged();
+    void modelCompletionChanged();
+    void modelChanged(size_t startFrame, size_t endFrame);
+    void modelReplaced();
+
+    void layerParametersChanged();
+    void layerNameChanged();
+
+protected:
+    View *m_view;
+};
+
+#endif
+