#ifndef SHADERSELECTOR_H_
#define SHADERSELECTOR_H_

#include <string>
#include <vector>
#include "gtkutil/glwidget.h"
#include "ishader.h"

/* FORWARD DECLS */
typedef struct _GtkListStore GtkListStore;
typedef struct _GtkWidget GtkWidget;
typedef struct _GtkTreeSelection GtkTreeSelection;
typedef struct _GdkEventExpose GdkEventExpose;

namespace ui
{

/** A widget that allows the selection of a shader. The widget contains
 * three elements - a tree view displaying available shaders as
 * identified by the specified prefixes, an OpenGL widget displaying a
 * preview of the currently-selected shader, and a table containing certain
 * information about the shader.
 *
 * Use the GtkWidget* operator to incorporate this class into a dialog window.
 *
 * This widget populates its list of shaders automatically, and offers a method
 * that allows calling code to retrieve the user's selection. The set of
 * displayed textures can be defined by passing a list of texture prefixes to
 * the constructor (comma-separated, e.g. "fog,light").
 *
 * The client class has to derive from the abstract ShaderSelector::Client class
 * providing an interface to allow the update of the info liststore.
 *
 * For convenience purposes, this class provides two static members that
 * allow populating the infostore widget with common lightshader/shader information.
 *
 */
class ShaderSelector
{
public:

	// Derive from this class to update the info widget
	class Client
	{
	public:
		/// destructor
		virtual ~Client() {}
		/** greebo: This gets invoked upon selection changed to allow the client
		 * 			class to display custom information in the selector's liststore.
		 */
		virtual void shaderSelectionChanged(const std::string& shader, GtkListStore* listStore) = 0;
	};

private:
	// Main widget container
	GtkWidget* _widget;

	// Tree view and selection object
	GtkWidget* _treeView;
	GtkTreeSelection* _selection;

	// GL preview widget
	gtkutil::GLWidget _glWidget;

	// List store for info table
	GtkListStore* _infoStore;

	// The client of this class.
	Client* _client;

public:
	// This is where the prefixes are stored (needed to filter the possible shaders)
	typedef std::vector<std::string> PrefixList;
	PrefixList _prefixes;

	/** Constructor.
	 *
	 * @param client: The client class that gets notified on selection change
	 * @param prefixes: A comma-separated list of shader prefixes.
	 * @param isLightTexture: set this to TRUE to render the light textures instead of the editor images
	 */
	ShaderSelector(Client* client, const std::string& prefixes, bool isLightTexture = false);

	/** Operator cast to GtkWidget*, for packing into parent widget.
	 */
	operator GtkWidget* () {
		return _widget;
	}

	/** Return the shader selected by the user, or an empty string if there
	 * was no selection.
	 */
	std::string getSelection();

	/** Set the given shader name as the current selection, highlighting it
	 * in the tree view.
	 *
	 * @param selection
	 * The fullname of the shader to select, or the empty string if there
	 * should be no selection.
	 */
	void setSelection(const std::string& selection);

	// Get the selected Material
	IShader* getSelectedShader();

	/** greebo: Static info display function (can be used by other UI classes as well
	 * 			to allow code reuse).
	 */
	static void displayShaderInfo(IShader* shader, GtkListStore* listStore);

private:

	// Create GUI elements
	GtkWidget* createTreeView();
	GtkWidget* createPreview();

	// Update the info in the table (passes the call to the client class)
	void updateInfoTable();

	/* GTK CALLBACKS */
	static void _onExpose(GtkWidget*, GdkEventExpose*, ShaderSelector*);
	static void _onSelChange(GtkWidget*, ShaderSelector*);
};

} // namespace ui

#endif /*SHADERSELECTOR_H_*/
