Add label annotation manager for label stacks

See #1801.

django/applications/catmaid/static/js/label-annotations.js

@@ -0,0 +1,132 @@
+(function (CATMAID) {
+
+  "use strict";
+
+  class LabelAnnotations {
+    constructor() {
+      this.managers = new Map();
+      this.active = undefined;
+    }
+
+    activate(stackID) {
+      this.active = stackID;
+    }
+
+    clear() {
+      for (const [_stack, manager] of this.managers.entries()) manager.unregister();
+      this.managers.clear();
+      this.active = undefined;
+    }
+
+    get(stack) {
+      let manager = this.managers.get(stack.id);
+
+      if (!manager) {
+        manager = new LabelStackAnnotations(stack);
+        this.managers.set(stack.id, manager);
+      }
+
+      return manager;
+    }
+  }
+
+  CATMAID.LabelAnnotations = new LabelAnnotations();
+
+  CATMAID.Init.on(CATMAID.Init.EVENT_PROJECT_CHANGED, CATMAID.LabelAnnotations.clear, CATMAID.LabelAnnotations);
+
+
+  const LABEL_FILTER_KEY = 'Object Label Color Map';
+
+  class LabelStackAnnotations {
+    constructor(
+      stack
+    ) {
+      this.stack = stack;
+      this.activeLabelID = undefined;
+      this.specialLabels = {
+        background: 0,
+      };
+      if (this.stack.metadata &&
+          this.stack.metadata.catmaidLabelMeta &&
+          this.stack.metadata.catmaidLabelMeta.specialLabels) {
+        $.extend(this.specialLabels, this.stack.metadata.catmaidLabelMeta.specialLabels);
+      }
+      this.stackLayerFilters = new Map();
+
+      project.on(CATMAID.Project.EVENT_STACKVIEW_ADDED,
+          this.registerStackViewerLayers, this);
+      CATMAID.StackViewer.on(CATMAID.StackViewer.EVENT_STACK_LAYER_ADDED,
+          this.registerStackLayer, this);
+      CATMAID.StackViewer.on(CATMAID.StackViewer.EVENT_STACK_LAYER_REMOVED,
+          this.unregisterStackLayer, this);
+    }
+
+    unregister() {
+      project.off(CATMAID.Project.EVENT_STACKVIEW_ADDED,
+          this.registerStackViewerLayers, this);
+      CATMAID.StackViewer.off(CATMAID.StackViewer.EVENT_STACK_LAYER_ADDED,
+          this.registerStackLayer, this);
+      CATMAID.StackViewer.off(CATMAID.StackViewer.EVENT_STACK_LAYER_REMOVED,
+          this.unregisterStackLayer, this);
+      this.stackLayerFilters.clear();
+    }
+
+    activateLabel(labelID) {
+      this.activeLabelID = labelID;
+
+      for (const [stackLayer, filter] of this.stackLayerFilters.entries()) {
+        this.updateFilter(filter);
+        stackLayer.redraw();
+        stackLayer.stackViewer.layercontrol.refresh();
+      }
+    }
+
+    registerAllStackLayers() {
+      for (const stackViewer of project.getStackViewers()) {
+        this.registerStackViewerLayers(stackViewer);
+      }
+    }
+
+    registerStackViewerLayers(stackViewer) {
+      for (const stackLayer of stackViewer.getLayersOfType(CATMAID.StackLayer)) {
+        this.registerStackLayer(stackLayer, stackViewer);
+      }
+    }
+
+    registerStackLayer(stackLayer, stackViewer) {
+      if (this.stack.id !== stackLayer.stack.id) return;
+
+      let layerFilters = stackLayer.getAvailableFilters ? stackLayer.getAvailableFilters() : [];
+      if (LABEL_FILTER_KEY in layerFilters && !this.stackLayerFilters.has(stackLayer)) {
+        stackLayer.setBlendMode('add');
+        stackLayer.setInterpolationMode(false);  // Nearest neighbor interpolation.
+        stackLayer.isHideable = true;
+        let filter = new (layerFilters[LABEL_FILTER_KEY])();
+        this.updateFilter(filter);
+        stackLayer.addFilter(filter);
+        this.stackLayerFilters.set(stackLayer, filter);
+
+        // TODO: coupling state refresh with stack viewer.
+        stackLayer.redraw();
+        stackViewer.layercontrol.refresh();
+      }
+    }
+
+    unregisterStackLayer(stackLayer, stackViewer) {
+      if (this.stack.id !== stackLayer.stack.id) return;
+
+      this.stackLayerFilters.delete(stackLayer);
+    }
+
+    updateFilter(filter) {
+      filter.pixiFilter.backgroundLabel = CATMAID.PixiLayer.Filters.int2arr(
+        this.specialLabels.background);
+      filter.pixiFilter.unknownLabel = typeof this.activeLabelID === 'undefined' ?
+        [-1, -1, -1, -1] :
+        CATMAID.PixiLayer.Filters.int2arr(this.activeLabelID);
+    }
+  }
+
+  CATMAID.LabelStackAnnotations = LabelStackAnnotations;
+
+})(CATMAID);

django/projects/mysite/pipelinefiles.py

@@ -179,6 +179,7 @@ def update(self, other_dict, key_prefix='catmaid-ext-'):
         'js/widgets/detail-dialog.js',
         'js/widgets/options-dialog.js',
         'js/3d/*.js',
+        'js/label-annotations.js',
         'js/widgets/*.js',
     ),
     'output_filename': 'js/catmaid.js',