1 files changed, 133 insertions, 0 deletions
diff --git a/toolkit/content/viewZoomOverlay.js b/toolkit/content/viewZoomOverlay.js
new file mode 100644
index 0000000000..877651a7b1
--- /dev/null
+++ b/toolkit/content/viewZoomOverlay.js
@@ -0,0 +1,133 @@
+// -*- indent-tabs-mode: nil; js-indent-level: 2 -*-
+
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/** Document Zoom Management Code
+ *
+ * To use this, you'll need to have a global gBrowser variable
+ * or use the methods that accept a browser to be modified.
+ **/
+
+var { Services } = ChromeUtils.import("resource://gre/modules/Services.jsm");
+
+var ZoomManager = {
+  get MIN() {
+    delete this.MIN;
+    return (this.MIN = Services.prefs.getIntPref("zoom.minPercent") / 100);
+  },
+
+  get MAX() {
+    delete this.MAX;
+    return (this.MAX = Services.prefs.getIntPref("zoom.maxPercent") / 100);
+  },
+
+  get useFullZoom() {
+    return Services.prefs.getBoolPref("browser.zoom.full");
+  },
+
+  set useFullZoom(aVal) {
+    Services.prefs.setBoolPref("browser.zoom.full", aVal);
+    return aVal;
+  },
+
+  get zoom() {
+    return this.getZoomForBrowser(gBrowser);
+  },
+
+  useFullZoomForBrowser: function ZoomManager_useFullZoomForBrowser(aBrowser) {
+    return this.useFullZoom || aBrowser.isSyntheticDocument;
+  },
+
+  getFullZoomForBrowser: function ZoomManager_getFullZoomForBrowser(aBrowser) {
+    if (!this.useFullZoomForBrowser(aBrowser)) {
+      return 1.0;
+    }
+    return this.getZoomForBrowser(aBrowser);
+  },
+
+  getZoomForBrowser: function ZoomManager_getZoomForBrowser(aBrowser) {
+    let zoom = this.useFullZoomForBrowser(aBrowser)
+      ? aBrowser.fullZoom
+      : aBrowser.textZoom;
+    // Round to remove any floating-point error.
+    return Number(zoom ? zoom.toFixed(2) : 1);
+  },
+
+  set zoom(aVal) {
+    this.setZoomForBrowser(gBrowser, aVal);
+    return aVal;
+  },
+
+  setZoomForBrowser: function ZoomManager_setZoomForBrowser(aBrowser, aVal) {
+    if (aVal < this.MIN || aVal > this.MAX) {
+      throw Components.Exception("", Cr.NS_ERROR_INVALID_ARG);
+    }
+
+    if (this.useFullZoomForBrowser(aBrowser)) {
+      aBrowser.textZoom = 1;
+      aBrowser.fullZoom = aVal;
+    } else {
+      aBrowser.textZoom = aVal;
+      aBrowser.fullZoom = 1;
+    }
+  },
+
+  get zoomValues() {
+    var zoomValues = Services.prefs
+      .getCharPref("toolkit.zoomManager.zoomValues")
+      .split(",")
+      .map(parseFloat);
+    zoomValues.sort((a, b) => a - b);
+
+    while (zoomValues[0] < this.MIN) {
+      zoomValues.shift();
+    }
+
+    while (zoomValues[zoomValues.length - 1] > this.MAX) {
+      zoomValues.pop();
+    }
+
+    delete this.zoomValues;
+    return (this.zoomValues = zoomValues);
+  },
+
+  enlarge: function ZoomManager_enlarge() {
+    var i = this.zoomValues.indexOf(this.snap(this.zoom)) + 1;
+    if (i < this.zoomValues.length) {
+      this.zoom = this.zoomValues[i];
+    }
+  },
+
+  reduce: function ZoomManager_reduce() {
+    var i = this.zoomValues.indexOf(this.snap(this.zoom)) - 1;
+    if (i >= 0) {
+      this.zoom = this.zoomValues[i];
+    }
+  },
+
+  reset: function ZoomManager_reset() {
+    this.zoom = 1;
+  },
+
+  toggleZoom: function ZoomManager_toggleZoom() {
+    var zoomLevel = this.zoom;
+
+    this.useFullZoom = !this.useFullZoom;
+    this.zoom = zoomLevel;
+  },
+
+  snap: function ZoomManager_snap(aVal) {
+    var values = this.zoomValues;
+    for (var i = 0; i < values.length; i++) {
+      if (values[i] >= aVal) {
+        if (i > 0 && aVal - values[i - 1] < values[i] - aVal) {
+          i--;
+        }
+        return values[i];
+      }
+    }
+    return values[i - 1];
+  },
+};