Chris@127: 
Chris@127: /* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */
Chris@127: 
Chris@127: /*
Chris@127:     Sonic Visualiser
Chris@127:     An audio file viewer and annotation editor.
Chris@127:     Centre for Digital Music, Queen Mary, University of London.
Chris@182:     This file copyright 2006 Chris Cannam and QMUL.
Chris@127:     
Chris@127:     This program is free software; you can redistribute it and/or
Chris@127:     modify it under the terms of the GNU General Public License as
Chris@127:     published by the Free Software Foundation; either version 2 of the
Chris@127:     License, or (at your option) any later version.  See the file
Chris@127:     COPYING included with this distribution for more information.
Chris@127: */
Chris@127: 
Chris@127: #ifndef _LAYER_H_
Chris@127: #define _LAYER_H_
Chris@127: 
Chris@128: #include "base/PropertyContainer.h"
Chris@128: #include "base/XmlExportable.h"
Chris@128: #include "base/Selection.h"
Chris@127: 
Chris@127: #include <QObject>
Chris@127: #include <QRect>
Chris@127: #include <QXmlAttributes>
Chris@131: #include <QMutex>
Chris@127: 
Chris@127: #include <map>
Chris@127: 
Chris@127: class ZoomConstraint;
Chris@127: class Model;
Chris@127: class QPainter;
Chris@127: class View;
Chris@127: class QMouseEvent;
Chris@127: class Clipboard;
Chris@127: 
Chris@127: /**
Chris@127:  * The base class for visual representations of the data found in a
Chris@127:  * Model.  Layers are expected to be able to draw themselves onto a
Chris@127:  * View, and may also be editable.
Chris@127:  */
Chris@127: 
Chris@127: class Layer : public PropertyContainer,
Chris@127: 	      public XmlExportable
Chris@127: {
Chris@127:     Q_OBJECT
Chris@127: 
Chris@127: public:
Chris@127:     Layer();
Chris@127:     virtual ~Layer();
Chris@127: 
Chris@127:     virtual const Model *getModel() const = 0;
Chris@127:     virtual Model *getModel() {
Chris@127: 	return const_cast<Model *>(const_cast<const Layer *>(this)->getModel());
Chris@127:     }
Chris@127: 
Chris@137:     /**
Chris@137:      * Return a zoom constraint object defining the supported zoom
Chris@137:      * levels for this layer.  If this returns zero, the layer will
Chris@137:      * support any integer zoom level.
Chris@137:      */
Chris@127:     virtual const ZoomConstraint *getZoomConstraint() const { return 0; }
Chris@137: 
Chris@137:     /**
Chris@137:      * Return true if this layer can handle zoom levels other than
Chris@137:      * those supported by its zoom constraint (presumably less
Chris@137:      * efficiently or accurately than the officially supported zoom
Chris@137:      * levels).  If true, the layer will unenthusistically accept any
Chris@137:      * integer zoom level from 1 to the maximum returned by its zoom
Chris@137:      * constraint.
Chris@137:      */
Chris@137:     virtual bool supportsOtherZoomLevels() const { return true; }
Chris@137: 
Chris@127:     virtual void paint(View *, QPainter &, QRect) const = 0;   
Chris@127: 
Chris@127:     enum VerticalPosition {
Chris@127: 	PositionTop, PositionMiddle, PositionBottom
Chris@127:     };
Chris@127:     virtual VerticalPosition getPreferredTimeRulerPosition() const {
Chris@127: 	return PositionMiddle;
Chris@127:     }
Chris@127:     virtual VerticalPosition getPreferredFrameCountPosition() const {
Chris@127: 	return PositionBottom;
Chris@127:     }
Chris@127: 
Chris@127:     virtual QString getPropertyContainerIconName() const;
Chris@127: 
Chris@127:     virtual QString getPropertyContainerName() const {
Chris@127: 	return objectName();
Chris@127:     }
Chris@127: 
Chris@127:     virtual QString getLayerPresentationName() const;
Chris@127: 
Chris@127:     virtual int getVerticalScaleWidth(View *, QPainter &) const { return 0; }
Chris@127:     virtual void paintVerticalScale(View *, QPainter &, QRect) const { }
Chris@127: 
Chris@127:     virtual bool getCrosshairExtents(View *, QPainter &, QPoint /* cursorPos */,
Chris@127:                                      std::vector<QRect> &) const {
Chris@127:         return false;
Chris@127:     }
Chris@127:     virtual void paintCrosshairs(View *, QPainter &, QPoint) const { }
Chris@127: 
Chris@127:     virtual QString getFeatureDescription(View *, QPoint &) const {
Chris@127: 	return "";
Chris@127:     }
Chris@127: 
Chris@127:     enum SnapType {
Chris@127: 	SnapLeft,
Chris@127: 	SnapRight,
Chris@127: 	SnapNearest,
Chris@127: 	SnapNeighbouring
Chris@127:     };
Chris@127: 
Chris@127:     /**
Chris@127:      * Adjust the given frame to snap to the nearest feature, if
Chris@127:      * possible.
Chris@127:      *
Chris@127:      * If snap is SnapLeft or SnapRight, adjust the frame to match
Chris@127:      * that of the nearest feature in the given direction regardless
Chris@127:      * of how far away it is.  If snap is SnapNearest, adjust the
Chris@127:      * frame to that of the nearest feature in either direction.  If
Chris@127:      * snap is SnapNeighbouring, adjust the frame to that of the
Chris@127:      * nearest feature if it is close, and leave it alone (returning
Chris@127:      * false) otherwise.  SnapNeighbouring should always choose the
Chris@127:      * same feature that would be used in an editing operation through
Chris@127:      * calls to editStart etc.
Chris@127:      *
Chris@127:      * Return true if a suitable feature was found and frame adjusted
Chris@180:      * accordingly.  Return false if no suitable feature was available
Chris@180:      * (and leave frame unmodified).  Also return the resolution of
Chris@180:      * the model in this layer in sample frames.
Chris@127:      */
Chris@127:     virtual bool snapToFeatureFrame(View *   /* v */,
Chris@127: 				    int &    /* frame */,
Chris@127: 				    size_t &resolution,
Chris@127: 				    SnapType /* snap */) const {
Chris@127: 	resolution = 1;
Chris@127: 	return false;
Chris@127:     }
Chris@127: 
Chris@127:     // Draw and edit modes:
Chris@127:     //
Chris@127:     // Layer needs to get actual mouse events, I guess.  Draw mode is
Chris@127:     // probably the easier.
Chris@127: 
Chris@127:     virtual void drawStart(View *, QMouseEvent *) { }
Chris@127:     virtual void drawDrag(View *, QMouseEvent *) { }
Chris@127:     virtual void drawEnd(View *, QMouseEvent *) { }
Chris@127: 
Chris@127:     virtual void editStart(View *, QMouseEvent *) { }
Chris@127:     virtual void editDrag(View *, QMouseEvent *) { }
Chris@127:     virtual void editEnd(View *, QMouseEvent *) { }
Chris@127: 
Chris@127:     virtual void editOpen(View *, QMouseEvent *) { } // on double-click
Chris@127: 
Chris@127:     virtual void moveSelection(Selection, size_t /* newStartFrame */) { }
Chris@127:     virtual void resizeSelection(Selection, Selection /* newSize */) { }
Chris@127:     virtual void deleteSelection(Selection) { }
Chris@127: 
Chris@127:     virtual void copy(Selection, Clipboard & /* to */) { }
Chris@127: 
Chris@127:     /**
Chris@127:      * Paste from the given clipboard onto the layer at the given
Chris@127:      * frame offset.  If interactive is true, the layer may ask the
Chris@127:      * user about paste options through a dialog if desired, and may
Chris@127:      * return false if the user cancelled the paste operation.  This
Chris@127:      * function should return true if a paste actually occurred.
Chris@127:      */
Chris@127:     virtual bool paste(const Clipboard & /* from */,
Chris@127:                        int /* frameOffset */,
Chris@127:                        bool /* interactive */) { return false; }
Chris@127: 
Chris@127:     // Text mode:
Chris@127:     //
Chris@127:     // Label nearest feature.  We need to get the feature coordinates
Chris@127:     // and current label from the layer, and then the pane can pop up
Chris@127:     // a little text entry dialog at the right location.  Or we edit
Chris@127:     // in place?  Probably the dialog is easier.
Chris@127: 
Chris@127:     /**
Chris@127:      * This should return true if the layer can safely be scrolled
Chris@127:      * automatically by a given view (simply copying the existing data
Chris@127:      * and then refreshing the exposed area) without altering its
Chris@127:      * meaning.  For the view widget as a whole this is usually not
Chris@127:      * possible because of invariant (non-scrolling) material
Chris@127:      * displayed over the top, but the widget may be able to optimise
Chris@127:      * scrolling better if it is known that individual views can be
Chris@127:      * scrolled safely in this way.
Chris@127:      */
Chris@127:     virtual bool isLayerScrollable(const View *) const { return true; }
Chris@127: 
Chris@127:     /**
Chris@127:      * This should return true if the layer completely obscures any
Chris@127:      * underlying layers.  It's used to determine whether the view can
Chris@127:      * safely draw any selection rectangles under the layer instead of
Chris@127:      * over it, in the case where the layer is not scrollable and
Chris@127:      * therefore needs to be redrawn each time (so that the selection
Chris@127:      * rectangle can be cached).
Chris@127:      */
Chris@127:     virtual bool isLayerOpaque() const { return false; }
Chris@127: 
Chris@127:     /**
Chris@183:      * This should return true if the layer uses colours to indicate
Chris@183:      * meaningful information (as opposed to just using a single
Chris@183:      * colour of the user's choice).  If this is the case, the view
Chris@183:      * will show selections using unfilled rectangles instead of
Chris@183:      * translucent filled rectangles, so as not to disturb the colours
Chris@183:      * underneath.
Chris@183:      */
Chris@183:     virtual bool isLayerColourSignificant() const { return false; }
Chris@183: 
Chris@183:     /**
Chris@127:      * This should return true if the layer can be edited by the user.
Chris@127:      * If this is the case, the appropriate edit tools may be made
Chris@127:      * available by the application and the layer's drawStart/Drag/End
Chris@127:      * and editStart/Drag/End methods should be implemented.
Chris@127:      */
Chris@127:     virtual bool isLayerEditable() const { return false; }
Chris@127: 
Chris@127:     /**
Chris@127:      * Return the proportion of background work complete in drawing
Chris@127:      * this view, as a percentage -- in most cases this will be the
Chris@127:      * value returned by pointer from a call to the underlying model's
Chris@127:      * isReady(int *) call.  The widget may choose to show a progress
Chris@127:      * meter if it finds that this returns < 100 at any given moment.
Chris@127:      */
Chris@127:     virtual int getCompletion(View *) const { return 100; }
Chris@127: 
Chris@127:     virtual void setObjectName(const QString &name);
Chris@127: 
Chris@127:     /**
Chris@127:      * Convert the layer's data (though not those of the model it
Chris@127:      * refers to) into an XML string for file output.  This class
Chris@127:      * implements the basic name/type/model-id output; subclasses will
Chris@127:      * typically call this superclass implementation with extra
Chris@127:      * attributes describing their particular properties.
Chris@127:      */
Chris@127:     virtual QString toXmlString(QString indent = "",
Chris@127: 				QString extraAttributes = "") const;
Chris@127: 
Chris@127:     /**
Chris@127:      * Set the particular properties of a layer (those specific to the
Chris@127:      * subclass) from a set of XML attributes.  This is the effective
Chris@127:      * inverse of the toXmlString method.
Chris@127:      */
Chris@127:     virtual void setProperties(const QXmlAttributes &) = 0;
Chris@127: 
Chris@127:     /**
Chris@127:      * Indicate that a layer is not currently visible in the given
Chris@127:      * view and is not expected to become visible in the near future
Chris@127:      * (for example because the user has explicitly removed or hidden
Chris@127:      * it).  The layer may respond by (for example) freeing any cache
Chris@127:      * memory it is using, until next time its paint method is called,
Chris@127:      * when it should set itself un-dormant again.
Chris@131:      *
Chris@131:      * A layer class that overrides this function must also call this
Chris@131:      * class's implementation.
Chris@127:      */
Chris@131:     virtual void setLayerDormant(const View *v, bool dormant);
Chris@127: 
Chris@127:     /**
Chris@127:      * Return whether the layer is dormant (i.e. hidden) in the given
Chris@127:      * view.
Chris@127:      */
Chris@131:     virtual bool isLayerDormant(const View *v) const;
Chris@127: 
Chris@127:     virtual PlayParameters *getPlayParameters();
Chris@127: 
Chris@127:     virtual bool needsTextLabelHeight() const { return false; }
Chris@127: 
Chris@127:     /**
Chris@127:      * Return the minimum and maximum values for the y axis of the
Chris@127:      * model in this layer, as well as whether the layer is configured
Chris@127:      * to use a logarithmic y axis display.  Also return the unit for
Chris@127:      * these values if known.
Chris@127:      *
Chris@127:      * This function returns the "normal" extents for the layer, not
Chris@127:      * necessarily the extents actually in use in the display.
Chris@127:      */
Chris@127:     virtual bool getValueExtents(float &min, float &max,
Chris@127:                                  bool &logarithmic, QString &unit) const = 0;
Chris@127: 
Chris@127:     /**
Chris@127:      * Return the minimum and maximum values within the displayed
Chris@127:      * range for the y axis, if only a subset of the whole range of
Chris@127:      * the model (returned by getValueExtents) is being displayed.
Chris@127:      * Return false if the layer is not imposing a particular display
Chris@127:      * extent (using the normal layer extents or deferring to whatever
Chris@127:      * is in use for the same units elsewhere in the view).
Chris@127:      */
Chris@127:     virtual bool getDisplayExtents(float & /* min */,
Chris@127:                                    float & /* max */) const {
Chris@127:         return false;
Chris@127:     }
Chris@127: 
Chris@127:     /**
Chris@127:      * Set the displayed minimum and maximum values for the y axis to
Chris@127:      * the given range, if supported.  Return false if not supported
Chris@127:      * on this layer (and set nothing).  In most cases, layers that
Chris@127:      * return false for getDisplayExtents should also return false for
Chris@127:      * this function.
Chris@127:      */
Chris@127:     virtual bool setDisplayExtents(float /* min */,
Chris@127:                                    float /* max */) {
Chris@127:         return false;
Chris@127:     }
Chris@127: 
Chris@133:     /**
Chris@133:      * Get the number of vertical zoom steps available for this layer.
Chris@133:      * If vertical zooming is not available, return 0.  The meaning of
Chris@133:      * "zooming" is entirely up to the layer -- changing the zoom
Chris@133:      * level may cause the layer to reset its display extents or
Chris@180:      * change another property such as display gain.  However, layers
Chris@180:      * are advised for consistency to treat smaller zoom steps as
Chris@180:      * "more distant" or "zoomed out" and larger ones as "closer" or
Chris@180:      * "zoomed in".
Chris@180:      * 
Chris@133:      * Layers that provide this facility should also emit the
Chris@133:      * verticalZoomChanged signal if their vertical zoom changes
Chris@133:      * due to factors other than setVerticalZoomStep being called.
Chris@133:      */
Chris@133:     virtual int getVerticalZoomSteps(int &defaultStep) const { return 0; }
Chris@133: 
Chris@133:     /**
Chris@133:      * Get the current vertical zoom step.  A layer may support finer
Chris@133:      * control over ranges etc than is available through the integer
Chris@133:      * zoom step mechanism; if this one does, it should just return
Chris@133:      * the nearest of the available zoom steps to the current settings.
Chris@133:      */
Chris@133:     virtual int getCurrentVerticalZoomStep() const { return 0; }
Chris@133: 
Chris@133:     /**
Chris@133:      * Set the vertical zoom step.  The meaning of "zooming" is
Chris@133:      * entirely up to the layer -- changing the zoom level may cause
Chris@133:      * the layer to reset its display extents or change another
Chris@133:      * property such as display gain.
Chris@133:      */
Chris@133:     virtual void setVerticalZoomStep(int) { }
Chris@133: 
Chris@127: public slots:
Chris@127:     void showLayer(View *, bool show);
Chris@127: 
Chris@127: signals:
Chris@127:     void modelChanged();
Chris@127:     void modelCompletionChanged();
Chris@127:     void modelChanged(size_t startFrame, size_t endFrame);
Chris@127:     void modelReplaced();
Chris@127: 
Chris@127:     void layerParametersChanged();
Chris@127:     void layerNameChanged();
Chris@127: 
Chris@133:     void verticalZoomChanged();
Chris@133: 
Chris@131: private:
Chris@131:     mutable QMutex m_dormancyMutex;
Chris@127:     mutable std::map<const void *, bool> m_dormancy;
Chris@127: };
Chris@127: 
Chris@127: #endif
Chris@127: