Print Preview: Adding UI for margin settings.

chrome/browser/resources/print_preview/margins_ui.js

+// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+cr.define('print_preview', function() {
+  'strict';
+
+  /**
+   * @constructor
+   * This class represents a margin line and a textbox corresponding to that
+   * margin.
+   */
+  function MarginsUIPair(groupName) {
+    this.line_ = new print_preview.MarginLine(groupName);
+    this.box_ = new print_preview.MarginTextbox(groupName);
+  }
+
+  MarginsUIPair.prototype = {
+    __proto__: MarginsUIPair.prototype,
+
+    /**
+     * Updates the state.
+     */
+    update: function(marginsRectangle, value, valueLimit, keepDisplayedValue) {
+      this.line_.update(marginsRectangle);
+      this.box_.update(marginsRectangle, value, valueLimit, keepDisplayedValue);
+    },
+
+    /**
+     * Draws |this| based on the state.
+     */
+    draw: function() {
+      this.line_.draw();
+      this.box_.draw();
+    }
+  };
+
+  function MarginsUI(parentNode) {
+    var marginsUI = document.createElement('div');
+    marginsUI.__proto__ = MarginsUI.prototype;
+    marginsUI.id = 'customized-margins';
+
+    marginsUI.topPair_ = new MarginsUIPair(
+        print_preview.MarginSettings.TOP_GROUP);
+    marginsUI.leftPair_ = new MarginsUIPair(
+        print_preview.MarginSettings.LEFT_GROUP);
+    marginsUI.rightPair_ = new MarginsUIPair(
+        print_preview.MarginSettings.RIGHT_GROUP);
+    marginsUI.bottomPair_ = new MarginsUIPair(
+        print_preview.MarginSettings.BOTTOM_GROUP);
+    parentNode.appendChild(marginsUI);
+
+    var uiPairs = marginsUI.pairsAsList;
+    for (var i = 0; i < uiPairs.length; i++) {
+      marginsUI.appendChild(uiPairs[i].line_);
+      marginsUI.appendChild(uiPairs[i].box_);
+    }
+    return marginsUI;
+  }
+
+  MarginsUI.prototype = {
+    __proto__: HTMLDivElement.prototype,
+
+    /**
+     * Adds an observer for |MarginsMayHaveChanged| event.
+     * @param {function} func A callback function to be called when
+     *   |MarginsMayHaveChanged| event occurs.
+     */
+    addObserver: function(func) {
+      var uiPairs = this.pairsAsList;
+      for (var i = 0; i < uiPairs.length; i++)
+        uiPairs[i].box_.addEventListener('MarginsMayHaveChanged', func);
+    },
+
+    /**
+     * @return {array} An array including all |MarginUIPair| objects.
+     */
+    get pairsAsList() {
+      return [this.topPair_, this.leftPair_, this.rightPair_, this.bottomPair_];
+    },
+
+    /**
+     * Updates the state of the margins UI.
+     * @param {print_preview.Rect}
+     * @param {Margins} marginValues
+     * @param {array} valueLimits
+     */
+    update: function(marginsRectangle, marginValues, valueLimits,
+        keepDisplayedValue) {
+      var uiPairs = this.pairsAsList;
+      var order = ['top', 'left', 'right', 'bottom'];
+      for (var i = 0; i < uiPairs.length; i++) {
+        uiPairs[i].update(marginsRectangle,
+                          marginValues[order[i]],
+                          valueLimits[i],
+                          keepDisplayedValue);
+      }
+    },
+
+    /**
+     * Draws |this| based on the latest state.
+     */
+    draw: function() {
+      this.applyClippingMask_();
+      this.pairsAsList.forEach(function(pair) { pair.draw(); });
+    },
+
+    /**
+     * Shows the margins UI.
+     */
+    show: function() {
+      this.hidden = false;
+    },
+
+    /**
+     * Hides the margins UI.
+     */
+    hide: function() {
+      this.hidden = true;
+    },
+
+    /**
+     * Applies a clipping mask on |this| so that it does not paint on top of the
+     * scrollbars (if any).
+     */
+    applyClippingMask_: function() {
+      var bottom = previewArea.height;
+      var right = previewArea.width;
+      this.style.clip = "rect(0, " + right + "px, " + bottom + "px, 0)";
+    }
+  };
+
+  return {
+    MarginsUI: MarginsUI
+  };
+});