view base/View.h @ 76:af2725b5d6fe

* Implement harmonic cursor in spectrogram
* Implement layer export.  This doesn't quite do the right thing for the SV
  XML layer export yet -- it doesn't include layer display information, so
  when imported, it only creates an invisible model.  Could also do with
  fixing CSV file import so as to work correctly for note and text layers.

/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */

/*
    Sonic Visualiser
    An audio file viewer and annotation editor.
    Centre for Digital Music, Queen Mary, University of London.
    This file copyright 2006 Chris Cannam.
    
    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.
*/

#ifndef _CANVAS_H_
#define _CANVAS_H_

#include <QFrame>
#include <QProgressBar>

#include "base/ZoomConstraint.h"
#include "base/PropertyContainer.h"
#include "base/ViewManager.h"
#include "base/XmlExportable.h"

// #define DEBUG_VIEW_WIDGET_PAINT 1

class Layer;
class ViewPropertyContainer;

#include <map>

/**
 * View is the base class of widgets that display one or more
 * overlaid views of data against a horizontal time scale. 
 *
 * A View may have any number of attached Layers, each of which
 * is expected to have one data Model (although multiple views may
 * share the same model).
 *
 * A View may be panned in time and zoomed, although the
 * mechanisms for doing so (as well as any other operations and
 * properties available) depend on the subclass.
 */

class View : public QFrame,
	     public XmlExportable
{
    Q_OBJECT

public:
    /**
     * Deleting a View does not delete any of its layers.  They should
     * be managed elsewhere (e.g. by the Document).
     */
    virtual ~View();

    /**
     * Retrieve the first visible sample frame on the widget.
     * This is a calculated value based on the centre-frame, widget
     * width and zoom level.  The result may be negative.
     */
    virtual long getStartFrame() const;

    /**
     * Set the widget pan based on the given first visible frame.  The
     * frame value may be negative.
     */
    virtual void setStartFrame(long);

    /**
     * Return the centre frame of the visible widget.  This is an
     * exact value that does not depend on the zoom block size.  Other
     * frame values (start, end) are calculated from this based on the
     * zoom and other factors.
     */
    virtual size_t getCentreFrame() const { return m_centreFrame; }

    /**
     * Set the centre frame of the visible widget.
     */
    virtual void setCentreFrame(size_t f) { setCentreFrame(f, true); }

    /**
     * Retrieve the last visible sample frame on the widget.
     * This is a calculated value based on the centre-frame, widget
     * width and zoom level.
     */
    virtual size_t getEndFrame() const;

    /**
     * Return the pixel x-coordinate corresponding to a given sample
     * frame (which may be negative).
     */
    int getXForFrame(long frame) const;

    /**
     * Return the closest frame to the given pixel x-coordinate.
     */
    long getFrameForX(int x) const;

    /**
     * Return the pixel y-coordinate corresponding to a given
     * frequency, if the frequency range is as specified.  This does
     * not imply any policy about layer frequency ranges, but it might
     * be useful for layers to match theirs up if desired.
     *
     * Not thread-safe in logarithmic mode.  Call only from GUI thread.
     */
    float getYForFrequency(float frequency, float minFreq, float maxFreq, 
			   bool logarithmic) const;

    /**
     * Return the closest frequency to the given pixel y-coordinate,
     * if the frequency range is as specified.
     *
     * Not thread-safe in logarithmic mode.  Call only from GUI thread.
     */
    float getFrequencyForY(int y, float minFreq, float maxFreq,
			   bool logarithmic) const;

    /**
     * Return the zoom level, i.e. the number of frames per pixel
     */
    int getZoomLevel() const;

    /**
     * Set the zoom level, i.e. the number of frames per pixel.  The
     * centre frame will be unchanged; the start and end frames will
     * change.
     */
    virtual void setZoomLevel(size_t z);

    /**
     * Zoom in or out.
     */
    virtual void zoom(bool in);

    /**
     * Scroll left or right by a smallish or largish amount.
     */
    virtual void scroll(bool right, bool lots);

    virtual void addLayer(Layer *v);
    virtual void removeLayer(Layer *v); // does not delete the layer
    virtual int getLayerCount() const { return m_layers.size(); }

    /**
     * Return a layer, counted in stacking order.  That is, layer 0 is
     * the bottom layer and layer "getLayerCount()-1" is the top one.
     */
    virtual Layer *getLayer(int n) { return m_layers[n]; }

    /**
     * Return the layer last selected by the user.  This is normally
     * the top layer, the same as getLayer(getLayerCount()-1).
     * However, if the user has selected the pane itself more recently
     * than any of the layers on it, this function will return 0.  It
     * will also return 0 if there are no layers.
     */
    virtual Layer *getSelectedLayer();
    virtual const Layer *getSelectedLayer() const;

    virtual void setViewManager(ViewManager *m);
    virtual ViewManager *getViewManager() const { return m_manager; }

    virtual void setFollowGlobalPan(bool f);
    virtual bool getFollowGlobalPan() const { return m_followPan; }

    virtual void setFollowGlobalZoom(bool f);
    virtual bool getFollowGlobalZoom() const { return m_followZoom; }

    virtual void setLightBackground(bool lb) { m_lightBackground = lb; }
    virtual bool hasLightBackground() const { return m_lightBackground; }

    enum TextStyle {
	BoxedText,
	OutlinedText
    };

    virtual void drawVisibleText(QPainter &p, int x, int y,
				 QString text, TextStyle style);

    virtual bool shouldIlluminateLocalFeatures(const Layer *, QPoint &) const {
	return false;
    }
    virtual bool shouldIlluminateLocalSelection(QPoint &, bool &, bool &) const {
	return false;
    }

    enum PlaybackFollowMode {
	PlaybackScrollContinuous,
	PlaybackScrollPage,
	PlaybackIgnore
    };
    virtual void setPlaybackFollow(PlaybackFollowMode m);
    virtual PlaybackFollowMode getPlaybackFollow() const { return m_followPlay; }

    typedef PropertyContainer::PropertyName PropertyName;

    // We implement the PropertyContainer API, although we don't
    // actually subclass PropertyContainer.  We have our own
    // PropertyContainer that we can return on request that just
    // delegates back to us.
    virtual PropertyContainer::PropertyList getProperties() const;
    virtual PropertyContainer::PropertyType getPropertyType(const PropertyName &) const;
    virtual int getPropertyRangeAndValue(const PropertyName &,
					 int *min, int *max) const;
    virtual QString getPropertyValueLabel(const PropertyName &,
					  int value) const;
    virtual void setProperty(const PropertyName &, int value);
    virtual QString getPropertyContainerName() const {
	return objectName();
    }
    virtual QString getPropertyContainerIconName() const = 0;

    virtual size_t getPropertyContainerCount() const;

    virtual const PropertyContainer *getPropertyContainer(size_t i) const;
    virtual PropertyContainer *getPropertyContainer(size_t i);

    virtual QString toXmlString(QString indent = "",
				QString extraAttributes = "") const;

    size_t getModelsStartFrame() const;
    size_t getModelsEndFrame() const;

signals:
    void propertyContainerAdded(PropertyContainer *pc);
    void propertyContainerRemoved(PropertyContainer *pc);
    void propertyContainerPropertyChanged(PropertyContainer *pc);
    void propertyContainerNameChanged(PropertyContainer *pc);
    void propertyChanged(PropertyName);

    void centreFrameChanged(void *, unsigned long, bool);
    void zoomLevelChanged(void *, unsigned long, bool);

public slots:
    virtual void modelChanged();
    virtual void modelChanged(size_t startFrame, size_t endFrame);
    virtual void modelCompletionChanged();
    virtual void modelReplaced();
    virtual void layerParametersChanged();
    virtual void layerNameChanged();

    virtual void viewManagerCentreFrameChanged(void *, unsigned long, bool);
    virtual void viewManagerPlaybackFrameChanged(unsigned long);
    virtual void viewManagerZoomLevelChanged(void *, unsigned long, bool);

    virtual void propertyContainerSelected(View *, PropertyContainer *pc);

    virtual void selectionChanged();
    virtual void toolModeChanged();

protected:
    View(QWidget *, bool showProgress);
    virtual void paintEvent(QPaintEvent *e);
    virtual void drawSelections(QPainter &);
    virtual bool shouldLabelSelections() const { return true; }

    typedef std::vector<Layer *> LayerList;

    int getModelsSampleRate() const;
    bool areLayersScrollable() const;
    LayerList getScrollableBackLayers(bool testChanged, bool &changed) const;
    LayerList getNonScrollableFrontLayers(bool testChanged, bool &changed) const;
    size_t getZoomConstraintBlockSize(size_t blockSize,
				      ZoomConstraint::RoundingDirection dir =
				      ZoomConstraint::RoundNearest) const;

    bool setCentreFrame(size_t f, bool doEmit);

    void checkProgress(void *object);

    size_t              m_centreFrame;
    int                 m_zoomLevel;
    bool                m_followPan;
    bool                m_followZoom;
    PlaybackFollowMode  m_followPlay;
    size_t              m_playPointerFrame;
    bool                m_lightBackground;
    bool                m_showProgress;

    QPixmap            *m_cache;
    size_t              m_cacheCentreFrame;
    int                 m_cacheZoomLevel;
    bool                m_selectionCached;

    bool                m_deleting;

    LayerList           m_layers; // I don't own these, but see dtor note above
    bool                m_haveSelectedLayer;

    // caches for use in getScrollableBackLayers, getNonScrollableFrontLayers
    mutable LayerList m_lastScrollableBackLayers;
    mutable LayerList m_lastNonScrollableBackLayers;

    class LayerProgressBar : public QProgressBar {
    public:
	LayerProgressBar(QWidget *parent);
	virtual QString text() const { return m_text; }
	virtual void setText(QString text) { m_text = text; }
    protected:
	QString m_text;
    };

    typedef std::map<Layer *, LayerProgressBar *> ProgressMap;
    ProgressMap m_progressBars; // I own the ProgressBars

    ViewManager *m_manager; // I don't own this
    ViewPropertyContainer *m_propertyContainer; // I own this
};


// Use this for delegation, because we can't subclass from
// PropertyContainer (which is a QObject) ourselves because of
// ambiguity with QFrame parent

class ViewPropertyContainer : public PropertyContainer
{
    Q_OBJECT

public:
    ViewPropertyContainer(View *v);
    PropertyList getProperties() const { return m_v->getProperties(); }
    PropertyType getPropertyType(const PropertyName &n) const {
	return m_v->getPropertyType(n);
    }
    int getPropertyRangeAndValue(const PropertyName &n, int *min, int *max) const {
	return m_v->getPropertyRangeAndValue(n, min, max);
    }
    QString getPropertyValueLabel(const PropertyName &n, int value) const {
	return m_v->getPropertyValueLabel(n, value);
    }
    QString getPropertyContainerName() const {
	return m_v->getPropertyContainerName();
    }
    QString getPropertyContainerIconName() const {
	return m_v->getPropertyContainerIconName();
    }

public slots:
    virtual void setProperty(const PropertyName &n, int value) {
	m_v->setProperty(n, value);
    }

protected:
    View *m_v;
};

#endif