comparison view/View.h @ 835:7792b7667f74

Introduce (but don't yet populate) the fixed layers vector; rename m_layers to m_layerStack to reflect its ordering by stacking

 
     /**
      * Return the number of layers, regardless of whether visible or
      * dormant, i.e. invisible, in this view.
      */
-    virtual int getLayerCount() const { return m_layers.size(); }
+    virtual int getLayerCount() const { return m_layerStack.size(); }
 
     /**
      * Return the nth layer, counted in stacking order.  That is,
      * layer 0 is the bottom layer and layer "getLayerCount()-1" is
      * the top one. The returned layer may be visible or it may be
      * dormant, i.e. invisible.
      */
     virtual Layer *getLayer(int n) {
-        if (n < int(m_layers.size())) return m_layers[n]; else return 0;
-    }
+        if (n < int(m_layerStack.size())) return m_layerStack[n];
+        else return 0;
+    }
+
+    /**
+     * Return the nth layer, counted in the order they were
+     * added. Unlike the stacking order used in getLayer(), which
+     * changes each time a layer is selected, this ordering remains
+     * fixed. The returned layer may be visible or it may be dormant,
+     * i.e. invisible.
+     */
+    virtual Layer *getFixedOrderLayer(int n) {
+        if (n < int(m_fixedOrderLayers.size())) return m_fixedOrderLayers[n];
+        else return 0;
+    }
+
+    /**
+     * Return the layer currently active for tool interaction. This is
+     * the topmost non-dormant (i.e. visible) layer in the view. If
+     * there are no visible layers in the view, return 0.
+     */
+    virtual Layer *getInteractionLayer();
+
+    /**
+     * Return the layer most recently selected by the user. This is
+     * the layer that any non-tool-driven commands should operate on,
+     * in the case where this view is the "current" one.
+     *
+     * If the user has selected the view itself more recently than any
+     * of the layers on it, this function will return 0, and any
+     * non-tool-driven layer commands should be deactivated while this
+     * view is current. It will also return 0 if there are no layers
+     * in the view.
+     *
+     * Note that, unlike getInteractionLayer(), this could return an
+     * invisible (dormant) layer.
+     */
+    virtual Layer *getSelectedLayer();
+
+    virtual const Layer *getSelectedLayer() const;
 
     /**
      * Return the "top" layer in the view, whether visible or dormant.
      * This is the same as getLayer(getLayerCount()-1) if there is at
      * least one layer, and 0 otherwise.
+     *
+     * For most purposes involving interaction or commands, you
+     * probably want either getInteractionLayer() or
+     * getSelectedLayer() instead.
      */
     virtual Layer *getTopLayer() {
-        return m_layers.empty() ? 0 : m_layers[m_layers.size()-1];
-    }
-
-    /**
-     * Return the layer currently active for tool interaction. This is
-     * the topmost non-dormant (i.e. visible) layer in the view. If
-     * there are no visible layers in the view, return 0.
-     */
-    virtual Layer *getInteractionLayer();
-
-    /**
-     * Return the layer most recently selected by the user. 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 in the view.
-     *
-     * Note that, unlike getInteractionLayer(), this could return an
-     * invisible (dormant) layer.
-     */
-    virtual Layer *getSelectedLayer();
-
-    virtual const Layer *getSelectedLayer() const;
+        return m_layerStack.empty() ? 0 : m_layerStack[m_layerStack.size()-1];
+    }
 
     virtual void setViewManager(ViewManager *m);
     virtual void setViewManager(ViewManager *m, int initialFrame);
     virtual ViewManager *getViewManager() const { return m_manager; }
 

     int                 m_cacheZoomLevel;
     bool                m_selectionCached;
 
     bool                m_deleting;
 
-    LayerList           m_layers; // I don't own these, but see dtor note above
+    LayerList           m_layerStack; // I don't own these, but see dtor note above
+    LayerList           m_fixedOrderLayers;
     bool                m_haveSelectedLayer;
 
     QString             m_lastError;
 
     // caches for use in getScrollableBackLayers, getNonScrollableFrontLayers