Refactor print preview web ui

chrome/browser/resources/print_preview/data/ticket_items/custom_margins.js

+// Copyright (c) 2012 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.ticket_items', function() {
+  'use strict';
+
+  /**
+   * Custom page margins ticket item whose value is a
+   * {@code print_preview.Margins}.
+   * @param {!print_preview.DocumentInfo} documentInfo Information about the
+   *     document to print.
+   * @param {!print_preview.MeasurementSystem} measurementSystem Used to convert
+   *     from string input into measurements in points.
+   * @constructor
+   * @extends {print_preview.ticket_items.TicketItem}
+   */
+  function CustomMargins(documentInfo, measurementSystem) {
+    print_preview.ticket_items.TicketItem.call(this);
+
+    /**
+     * Information about the document to print.
+     * @type {!print_preview.DocumentInfo}
+     * @private
+     */
+    this.documentInfo_ = documentInfo;
+
+    /**
+     * Used to convert from string input to measurements in points.
+     * @type {!print_preview.MeasurementSystem}
+     * @private
+     */
+    this.measurementSystem_ = measurementSystem;
+  };
+
+  /**
+   * Enumeration of the orientations of margins.
+   * @enum {string}
+   */
+  CustomMargins.Orientation = {
+    TOP: 'top',
+    RIGHT: 'right',
+    BOTTOM: 'bottom',
+    LEFT: 'left'
+  };
+
+  /**
+   * Mapping of a margin orientation to its opposite.
+   * @type {object.<CustomMargins.Orientation, CustomMargins.Orientation>}
+   * @private
+   */
+  CustomMargins.OppositeOrientation_ = {};
+  CustomMargins.OppositeOrientation_[CustomMargins.Orientation.TOP] =
+      CustomMargins.Orientation.BOTTOM;
+  CustomMargins.OppositeOrientation_[CustomMargins.Orientation.RIGHT] =
+      CustomMargins.Orientation.LEFT;
+  CustomMargins.OppositeOrientation_[CustomMargins.Orientation.BOTTOM] =
+      CustomMargins.Orientation.TOP;
+  CustomMargins.OppositeOrientation_[CustomMargins.Orientation.LEFT] =
+      CustomMargins.Orientation.RIGHT;
+
+  /**
+   * Minimum distance in points that two margins can be separated by.
+   * @type {number}
+   * @const
+   * @private
+   */
+  CustomMargins.MINIMUM_MARGINS_DISTANCE_ = 72; // 1 inch.
+
+  CustomMargins.prototype = {
+    __proto__: print_preview.ticket_items.TicketItem.prototype,
+
+    /** @override */
+    wouldValueBeValid: function(value) {
+      var margins = /** @type {!print_preview.Margins} */ (value);
+      for (var key in CustomMargins.Orientation) {
+        var o = CustomMargins.Orientation[key];
+        var max = this.getMarginMax_(
+            o, margins.get(CustomMargins.OppositeOrientation_[o]));
+        if (margins.get(o) > max || margins.get(o) < 0) {
+          return false;
+        }
+      }
+      return true;
+    },
+
+    /** @override */
+    isCapabilityAvailable: function() {
+      return this.documentInfo_.isModifiable;
+    },
+
+    /**
+     * @param {print_preview.ticket_items.CustomMargins.Orientation} orientation
+     *     Specifies the margin to get the maximum value for.
+     * @return {number} Maximum value in points of the specified margin.
+     */
+    getMarginMax: function(orientation) {
+      var oppositeOrient = CustomMargins.OppositeOrientation_[orientation];
+      var margins = /** @type {!print_preview.Margins} */ (this.getValue());
+      return this.getMarginMax_(orientation, margins.get(oppositeOrient));
+    },
+
+    /** @override */
+    updateValue: function(value) {
+      var margins = /** @type {!InputMargins} */ (value);
+      if (margins != null) {
+        margins = new print_preview.Margins(
+            Math.round(margins.get(CustomMargins.Orientation.TOP)),
+            Math.round(margins.get(CustomMargins.Orientation.RIGHT)),
+            Math.round(margins.get(CustomMargins.Orientation.BOTTOM)),
+            Math.round(margins.get(CustomMargins.Orientation.LEFT)));
+      }
+      print_preview.ticket_items.TicketItem.prototype.updateValue.call(
+          this, margins);
+    },
+
+    /**
+     * Updates the specified margin in points while keeping the value within
+     * a maximum and minimum.
+     * @param {print_preview.ticket_items.CustomMargins.Orientation} orientation
+     *     Specifies the margin to update.
+     * @param {number} value Updated margin value in points.
+     */
+    updateMargin: function(orientation, value) {
+      var margins = /** @type {!print_preview.Margins} */ (this.getValue());
+      var oppositeOrientation = CustomMargins.OppositeOrientation_[orientation];
+      var max =
+          this.getMarginMax_(orientation, margins.get(oppositeOrientation));
+      value = Math.max(0, Math.min(max, value));
+      this.updateValue(margins.set(orientation, value));
+    },
+
+    /** @override */
+    getDefaultValueInternal: function() {
+      return this.documentInfo_.margins ||
+             new print_preview.Margins(72, 72, 72, 72);
+    },
+
+    /** @override */
+    getCapabilityNotAvailableValueInternal: function() {
+      return this.documentInfo_.margins ||
+             new print_preview.Margins(72, 72, 72, 72);
+    },
+
+    /**
+     * @param {print_preview.ticket_items.CustomMargins.Orientation} orientation
+     *     Specifies which margin to get the maximum value of.
+     * @param {number} oppositeMargin Value of the margin in points
+     *     opposite the specified margin.
+     * @return {number} Maximum value in points of the specified margin.
+     * @private
+     */
+    getMarginMax_: function(orientation, oppositeMargin) {
+      var max;
+      if (orientation == CustomMargins.Orientation.TOP ||
+          orientation == CustomMargins.Orientation.BOTTOM) {
+        max = this.documentInfo_.pageSize.height - oppositeMargin -
+            CustomMargins.MINIMUM_MARGINS_DISTANCE_;
+      } else {
+        max = this.documentInfo_.pageSize.width - oppositeMargin -
+            CustomMargins.MINIMUM_MARGINS_DISTANCE_;
+      }
+      return Math.round(max);
+    }
+  };
+
+  // Export
+  return {
+    CustomMargins: CustomMargins
+  };
+});