michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: "use strict";
michael@0: const {classes: Cc, interfaces: Ci, utils: Cu, results: Cr} = Components;
michael@0: 
michael@0: this.EXPORTED_SYMBOLS = ["PanelWideWidgetTracker"];
michael@0: 
michael@0: Cu.import("resource://gre/modules/XPCOMUtils.jsm");
michael@0: XPCOMUtils.defineLazyModuleGetter(this, "CustomizableUI",
michael@0:   "resource:///modules/CustomizableUI.jsm");
michael@0: 
michael@0: let gModuleName = "[PanelWideWidgetTracker]";
michael@0: #include logging.js
michael@0: 
michael@0: let gPanel = CustomizableUI.AREA_PANEL;
michael@0: // We keep track of the widget placements for the panel locally:
michael@0: let gPanelPlacements = [];
michael@0: 
michael@0: // All the wide widgets we know of:
michael@0: let gWideWidgets = new Set();
michael@0: // All the widgets we know of:
michael@0: let gSeenWidgets = new Set();
michael@0: 
michael@0: let PanelWideWidgetTracker = {
michael@0:   // Listeners used to validate panel contents whenever they change:
michael@0:   onWidgetAdded: function(aWidgetId, aArea, aPosition) {
michael@0:     if (aArea == gPanel) {
michael@0:       gPanelPlacements = CustomizableUI.getWidgetIdsInArea(gPanel);
michael@0:       let moveForward = this.shouldMoveForward(aWidgetId, aPosition);
michael@0:       this.adjustWidgets(aWidgetId, moveForward);
michael@0:     }
michael@0:   },
michael@0:   onWidgetMoved: function(aWidgetId, aArea, aOldPosition, aNewPosition) {
michael@0:     if (aArea == gPanel) {
michael@0:       gPanelPlacements = CustomizableUI.getWidgetIdsInArea(gPanel);
michael@0:       let moveForward = this.shouldMoveForward(aWidgetId, aNewPosition);
michael@0:       this.adjustWidgets(aWidgetId, moveForward);
michael@0:     }
michael@0:   },
michael@0:   onWidgetRemoved: function(aWidgetId, aPrevArea) {
michael@0:     if (aPrevArea == gPanel) {
michael@0:       gPanelPlacements = CustomizableUI.getWidgetIdsInArea(gPanel);
michael@0:       let pos = gPanelPlacements.indexOf(aWidgetId);
michael@0:       this.adjustWidgets(aWidgetId, false);
michael@0:     }
michael@0:   },
michael@0:   onWidgetReset: function(aWidgetId) {
michael@0:     gPanelPlacements = CustomizableUI.getWidgetIdsInArea(gPanel);
michael@0:   },
michael@0:   // Listener to keep abreast of any new nodes. We use the DOM one because
michael@0:   // we need access to the actual node's classlist, so we can't use the ones above.
michael@0:   // Furthermore, onWidgetCreated only fires for API-based widgets, not for XUL ones.
michael@0:   onWidgetAfterDOMChange: function(aNode, aNextNode, aContainer) {
michael@0:     if (!gSeenWidgets.has(aNode.id)) {
michael@0:       if (aNode.classList.contains(CustomizableUI.WIDE_PANEL_CLASS)) {
michael@0:         gWideWidgets.add(aNode.id);
michael@0:       }
michael@0:       gSeenWidgets.add(aNode.id);
michael@0:     }
michael@0:   },
michael@0:   // When widgets get destroyed, we remove them from our sets of stuff we care about:
michael@0:   onWidgetDestroyed: function(aWidgetId) {
michael@0:     gSeenWidgets.delete(aWidgetId);
michael@0:     gWideWidgets.delete(aWidgetId);
michael@0:   },
michael@0:   shouldMoveForward: function(aWidgetId, aPosition) {
michael@0:     let currentWidgetAtPosition = gPanelPlacements[aPosition + 1];
michael@0:     let rv = gWideWidgets.has(currentWidgetAtPosition) && !gWideWidgets.has(aWidgetId);
michael@0:     // We might now think we can move forward, but for that we need at least 2 more small
michael@0:     // widgets to be present:
michael@0:     if (rv) {
michael@0:       let furtherWidgets = gPanelPlacements.slice(aPosition + 2);
michael@0:       let realWidgets = 0;
michael@0:       if (furtherWidgets.length >= 2) {
michael@0:         while (furtherWidgets.length && realWidgets < 2) {
michael@0:           let w = furtherWidgets.shift();
michael@0:           if (!gWideWidgets.has(w) && this.checkWidgetStatus(w)) {
michael@0:             realWidgets++;
michael@0:           }
michael@0:         }
michael@0:       }
michael@0:       if (realWidgets < 2) {
michael@0:         rv = false;
michael@0:       }
michael@0:     }
michael@0:     return rv;
michael@0:   },
michael@0:   adjustWidgets: function(aWidgetId, aMoveForwards) {
michael@0:     if (this.adjusting) {
michael@0:       return;
michael@0:     }
michael@0:     this.adjusting = true;
michael@0:     let widgetsAffected = [w for (w of gPanelPlacements) if (gWideWidgets.has(w))];
michael@0:     // If we're moving the wide widgets forwards (down/to the right in the panel)
michael@0:     // we want to start with the last widgets. Otherwise we move widgets over other wide
michael@0:     // widgets, which might mess up their order. Likewise, if moving backwards we should start with
michael@0:     // the first widget and work our way down/right from there.
michael@0:     let compareFn = aMoveForwards ? (function(a, b) a < b) : (function(a, b) a > b)
michael@0:     widgetsAffected.sort(function(a, b) compareFn(gPanelPlacements.indexOf(a),
michael@0:                                                   gPanelPlacements.indexOf(b)));
michael@0:     for (let widget of widgetsAffected) {
michael@0:       this.adjustPosition(widget, aMoveForwards);
michael@0:     }
michael@0:     this.adjusting = false;
michael@0:   },
michael@0:   // This function is called whenever an item gets moved in the menu panel. It
michael@0:   // adjusts the position of widgets within the panel to prevent "gaps" between
michael@0:   // wide widgets that could be filled up with single column widgets
michael@0:   adjustPosition: function(aWidgetId, aMoveForwards) {
michael@0:     // Make sure that there are n % columns = 0 narrow buttons before the widget.
michael@0:     let placementIndex = gPanelPlacements.indexOf(aWidgetId);
michael@0:     let prevSiblingCount = 0;
michael@0:     let fixedPos = null;
michael@0:     while (placementIndex--) {
michael@0:       let thisWidgetId = gPanelPlacements[placementIndex];
michael@0:       if (gWideWidgets.has(thisWidgetId)) {
michael@0:         continue;
michael@0:       }
michael@0:       let widgetStatus = this.checkWidgetStatus(thisWidgetId);
michael@0:       if (!widgetStatus) {
michael@0:         continue;
michael@0:       }
michael@0:       if (widgetStatus == "public-only") {
michael@0:         fixedPos = !fixedPos ? placementIndex : Math.min(fixedPos, placementIndex);
michael@0:         prevSiblingCount = 0;
michael@0:       } else {
michael@0:         prevSiblingCount++;
michael@0:       }
michael@0:     }
michael@0: 
michael@0:     if (fixedPos !== null || prevSiblingCount % CustomizableUI.PANEL_COLUMN_COUNT) {
michael@0:       let desiredPos = (fixedPos !== null) ? fixedPos : gPanelPlacements.indexOf(aWidgetId);
michael@0:       let desiredChange = -(prevSiblingCount % CustomizableUI.PANEL_COLUMN_COUNT);
michael@0:       if (aMoveForwards && fixedPos == null) {
michael@0:         // +1 because otherwise we'd count ourselves:
michael@0:         desiredChange = CustomizableUI.PANEL_COLUMN_COUNT + desiredChange + 1;
michael@0:       }
michael@0:       desiredPos += desiredChange;
michael@0:       CustomizableUI.moveWidgetWithinArea(aWidgetId, desiredPos);
michael@0:     }
michael@0:   },
michael@0: 
michael@0:   /*
michael@0:    * Check whether a widget id is actually known anywhere.
michael@0:    * @returns false if the widget doesn't exist,
michael@0:    *          "public-only" if it's not shown in private windows
michael@0:    *          "real" if it does exist and is shown even in private windows
michael@0:    */
michael@0:   checkWidgetStatus: function(aWidgetId) {
michael@0:     let widgetWrapper = CustomizableUI.getWidget(aWidgetId);
michael@0:     // This widget might not actually exist:
michael@0:     if (!widgetWrapper) {
michael@0:       return false;
michael@0:     }
michael@0:     // This widget might still not actually exist:
michael@0:     if (widgetWrapper.provider == CustomizableUI.PROVIDER_XUL &&
michael@0:         widgetWrapper.instances.length == 0) {
michael@0:       return false;
michael@0:     }
michael@0: 
michael@0:     // Or it might only be there some of the time:
michael@0:     if (widgetWrapper.provider == CustomizableUI.PROVIDER_API &&
michael@0:         widgetWrapper.showInPrivateBrowsing === false) {
michael@0:       return "public-only";
michael@0:     }
michael@0:     return "real";
michael@0:   },
michael@0: 
michael@0:   init: function() {
michael@0:     // Initialize our local placements copy and register the listener
michael@0:     gPanelPlacements = CustomizableUI.getWidgetIdsInArea(gPanel);
michael@0:     CustomizableUI.addListener(this);
michael@0:   },
michael@0: };