annotate document/Document.h @ 45:6b6bca31ad53

* When setting a new model on a layer, don't delete the old one until after
  the new one has been set (a layer's setModel may want to compare against the
  old one, as WaveformLayer does)

/* -*- 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 _DOCUMENT_H_
#define _DOCUMENT_H_

#include "layer/LayerFactory.h"
#include "transform/Transform.h"
#include "transform/PluginTransform.h"
#include "base/Command.h"

#include <map>
#include <set>

class Model;
class Layer;
class View;
class WaveFileModel;

/**
 * A Sonic Visualiser document consists of a set of data models, and
 * also the visualisation layers used to display them.  Changes to the
 * layers and their layout need to be stored and managed in much the
 * same way as changes to the underlying data.
 * 
 * The document manages:
 * 
 * -- A main data model, which provides the underlying sample rate and
 * such like.  This must be a wave file model.
 * 
 * -- Any number of imported models, which contain data without any
 * requirement to remember where the data came from or how to
 * regenerate it.
 * 
 * -- Any number of models generated by transforms such as feature
 * extraction plugins.  For these, we also record the source model and
 * the name of the transform used to generate the model so that we can
 * regenerate it (potentially from a different source) on demand.
 *
 * -- A flat list of layers.  Elsewhere, the GUI may distribute these
 * across any number of view widgets.  A layer may be viewable on more
 * than one view at once, in principle.  A layer refers to one model,
 * but the same model can be in use in more than one layer.
 *
 * The document does *not* manage the existence or structure of Pane
 * and other view widgets.  However, it does provide convenience
 * methods for reference-counted command-based management of the
 * association between layers and views (addLayerToView,
 * removeLayerFromView).
 */

class Document : public QObject,
		 public XmlExportable
{
    Q_OBJECT

public:
    Document();
    virtual ~Document();

    /**
     * Create and return a new layer of the given type, associated
     * with no model.  The caller may set any model on this layer, but
     * the model must also be registered with the document via the
     * add-model methods below.
     */
    Layer *createLayer(LayerFactory::LayerType);

    /**
     * Create and return a new layer of the given type, associated
     * with the current main model (if appropriate to the layer type).
     */
    Layer *createMainModelLayer(LayerFactory::LayerType);

    /**
     * Create and return a new layer associated with the given model,
     * and register the model as an imported model.
     */
    Layer *createImportedLayer(Model *);

    /**
     * Create and return a new layer of the given type, with an
     * appropriate empty model.  If the given type is not one for
     * which an empty model can meaningfully be created, return 0.
     */
    Layer *createEmptyLayer(LayerFactory::LayerType);

    /**
     * Create and return a new layer of the given type, associated
     * with the given transform name.  This method does not run the
     * transform itself, nor create a model.  The caller can safely
     * add a model to the layer later, but note that all models used
     * by a transform layer _must_ be registered with the document
     * using addDerivedModel below.
     */
    Layer *createDerivedLayer(LayerFactory::LayerType, TransformName);

    /**
     * Create and return a suitable layer for the given transform,
     * running the transform and associating the resulting model with
     * the new layer.
     */
    Layer *createDerivedLayer(TransformName,
                              Model *inputModel, 
                              const PluginTransform::ExecutionContext &context,
                              QString configurationXml);

    /**
     * Set the main model (the source for playback sample rate, etc)
     * to the given wave file model.  This will regenerate any derived
     * models that were based on the previous main model.
     */
    void setMainModel(WaveFileModel *);

    /**
     * Get the main model (the source for playback sample rate, etc).
     */
    WaveFileModel *getMainModel() { return m_mainModel; }

    /**
     * Add a derived model associated with the given transform name.
     * This is necessary to register any derived model that was not
     * created by the document using
     * e.g. createDerivedLayer(TransformName) above.
     */
    void addDerivedModel(TransformName,
                         Model *inputModel,
                         const PluginTransform::ExecutionContext &context,
                         Model *outputModelToAdd,
                         QString configurationXml);

    /**
     * Add an imported (non-derived, non-main) model.  This is
     * necessary to register any imported model that is associated
     * with a layer.
     */
    void addImportedModel(Model *);

    /**
     * Associate the given model with the given layer.  The model must
     * have already been registered using one of the addXXModel
     * methods above.
     */
    void setModel(Layer *, Model *);

    /**
     * Set the given layer to use the given channel of its model (-1
     * means all available channels).
     */
    void setChannel(Layer *, int);

    /**
     * Add the given layer to the given view.  If the layer is
     * intended to show a particular model, the model should normally
     * be set using setModel before this method is called.
     */
    void addLayerToView(View *, Layer *);

    /**
     * Remove the given layer from the given view.
     */
    void removeLayerFromView(View *, Layer *);

    void toXml(QTextStream &, QString indent, QString extraAttributes) const;
    QString toXmlString(QString indent, QString extraAttributes) const;

signals:
    void layerAdded(Layer *);
    void layerRemoved(Layer *);
    void layerAboutToBeDeleted(Layer *);

    // Emitted when a layer is first added to a view, or when it is
    // last removed from a view
    void layerInAView(Layer *, bool);

    void modelAdded(Model *);
    void mainModelChanged(WaveFileModel *); // emitted after modelAdded
    void modelAboutToBeDeleted(Model *);

    void modelGenerationFailed(QString transformName);
    void modelRegenerationFailed(QString layerName, QString transformName);

protected:
    Model *createModelForTransform(TransformName transform,
                                   Model *inputModel,
                                   const PluginTransform::ExecutionContext &context,
                                   QString configurationXml);
    void releaseModel(Model *model);

    /**
     * Delete the given layer, and also its associated model if no
     * longer used by any other layer.  In general, this should be the
     * only method used to delete layers -- doing so directly is a bit
     * of a social gaffe.
     */
    void deleteLayer(Layer *, bool force = false);

    /*
     * Every model that is in use by a layer in the document must be
     * found in either m_mainModel, m_derivedModels or
     * m_importedModels.  We own and control the lifespan of all of
     * these models.
     */

    /**
     * The model that provides the underlying sample rate, etc.  This
     * model is not reference counted for layers, and is not freed
     * unless it is replaced or the document is deleted.
     */
    WaveFileModel *m_mainModel;

    struct ModelRecord
    {
	// Information associated with a non-main model.  If this
	// model is derived from another, then source will be non-NULL
	// and the transform name will be set appropriately.  If the
	// transform name is set but source is NULL, then there was a
	// transform involved but the (target) model has been modified
	// since being generated from it.
	const Model *source;
	TransformName transform;
        PluginTransform::ExecutionContext context;
        QString configurationXml;

	// Count of the number of layers using this model.
	int refcount;
    };

    typedef std::map<Model *, ModelRecord> ModelMap;
    ModelMap m_models;

    class AddLayerCommand : public Command
    {
    public:
	AddLayerCommand(Document *d, View *view, Layer *layer);
	virtual ~AddLayerCommand();
	
	virtual void execute();
	virtual void unexecute();
	virtual QString getName() const { return m_name; }

    protected:
	Document *m_d;
	View *m_view; // I don't own this
	Layer *m_layer; // Document owns this, but I determine its lifespans
	QString m_name;
	bool m_added;
    };

    class RemoveLayerCommand : public Command
    {
    public:
	RemoveLayerCommand(Document *d, View *view, Layer *layer);
	virtual ~RemoveLayerCommand();
	
	virtual void execute();
	virtual void unexecute();
	virtual QString getName() const { return m_name; }

    protected:
	Document *m_d;
	View *m_view; // I don't own this
	Layer *m_layer; // Document owns this, but I determine its lifespan
	QString m_name;
	bool m_added;
    };

    typedef std::map<Layer *, std::set<View *> > LayerViewMap;
    LayerViewMap m_layerViewMap;

    void addToLayerViewMap(Layer *, View *);
    void removeFromLayerViewMap(Layer *, View *);

    QString getUniqueLayerName(QString candidate);
    
    /**
     * And these are the layers.  We also control the lifespans of
     * these (usually through the commands used to add and remove them).
     */
    typedef std::set<Layer *> LayerSet;
    LayerSet m_layers;
};

#endif