src/chrome/browser/resources/net_internals/resizable_vertical_split_view.js

   1 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 /**
   6  * This view implements a vertically split display with a draggable divider.
   7  *
   8  *                  <<-- sizer -->>
   9  *
  10  *  +----------------------++----------------+
  11  *  |                      ||                |
  12  *  |                      ||                |
  13  *  |                      ||                |
  14  *  |                      ||                |
  15  *  |       leftView       ||   rightView    |
  16  *  |                      ||                |
  17  *  |                      ||                |
  18  *  |                      ||                |
  19  *  |                      ||                |
  20  *  |                      ||                |
  21  *  +----------------------++----------------+
  22  *
  23  * @param {!View} leftView The widget to position on the left.
  24  * @param {!View} rightView The widget to position on the right.
  25  * @param {!DivView} sizerView The widget that will serve as draggable divider.
  26  */
  27 var ResizableVerticalSplitView = (function() {
  28   'use strict';
  29
  30   // Minimum width to size panels to, in pixels.
  31   var MIN_PANEL_WIDTH = 50;
  32
  33   // We inherit from View.
  34   var superClass = View;
  35
  36   /**
  37    * @constructor
  38    */
  39   function ResizableVerticalSplitView(leftView, rightView, sizerView) {
  40     // Call superclass's constructor.
  41     superClass.call(this);
  42
  43     this.leftView_ = leftView;
  44     this.rightView_ = rightView;
  45     this.sizerView_ = sizerView;
  46
  47     this.mouseDragging_ = false;
  48     this.touchDragging_ = false;
  49
  50     // Setup the "sizer" so it can be dragged left/right to reposition the
  51     // vertical split.  The start event must occur within the sizer's node,
  52     // but subsequent events may occur anywhere.
  53     var node = sizerView.getNode();
  54     node.addEventListener('mousedown', this.onMouseDragSizerStart_.bind(this));
  55     window.addEventListener('mousemove', this.onMouseDragSizer_.bind(this));
  56     window.addEventListener('mouseup', this.onMouseDragSizerEnd_.bind(this));
  57
  58     node.addEventListener('touchstart', this.onTouchDragSizerStart_.bind(this));
  59     window.addEventListener('touchmove', this.onTouchDragSizer_.bind(this));
  60     window.addEventListener('touchend', this.onTouchDragSizerEnd_.bind(this));
  61     window.addEventListener('touchcancel',
  62                             this.onTouchDragSizerEnd_.bind(this));
  63   }
  64
  65   ResizableVerticalSplitView.prototype = {
  66     // Inherit the superclass's methods.
  67     __proto__: superClass.prototype,
  68
  69     /**
  70      * Sets the width of the left view.
  71      * @param {Integer} px The number of pixels
  72      */
  73     setLeftSplit: function(px) {
  74       this.leftSplit_ = px;
  75     },
  76
  77     /**
  78      * Repositions all of the elements to fit the window.
  79      */
  80     setGeometry: function(left, top, width, height) {
  81       superClass.prototype.setGeometry.call(this, left, top, width, height);
  82
  83       // If this is the first setGeometry(), initialize the split point at 50%.
  84       if (!this.leftSplit_)
  85         this.leftSplit_ = parseInt((width / 2).toFixed(0));
  86
  87       // Calculate the horizontal split points.
  88       var leftboxWidth = this.leftSplit_;
  89       var sizerWidth = this.sizerView_.getWidth();
  90       var rightboxWidth = width - (leftboxWidth + sizerWidth);
  91
  92       // Don't let the right pane get too small.
  93       if (rightboxWidth < MIN_PANEL_WIDTH) {
  94         rightboxWidth = MIN_PANEL_WIDTH;
  95         leftboxWidth = width - (sizerWidth + rightboxWidth);
  96       }
  97
  98       // Position the boxes using calculated split points.
  99       this.leftView_.setGeometry(left, top, leftboxWidth, height);
 100       this.sizerView_.setGeometry(this.leftView_.getRight(), top,
 101                                   sizerWidth, height);
 102       this.rightView_.setGeometry(this.sizerView_.getRight(), top,
 103                                   rightboxWidth, height);
 104     },
 105
 106     show: function(isVisible) {
 107       superClass.prototype.show.call(this, isVisible);
 108       this.leftView_.show(isVisible);
 109       this.sizerView_.show(isVisible);
 110       this.rightView_.show(isVisible);
 111     },
 112
 113     /**
 114      * Called once the sizer is clicked on. Starts moving the sizer in response
 115      * to future mouse movement.
 116      */
 117     onMouseDragSizerStart_: function(event) {
 118       this.mouseDragging_ = true;
 119       event.preventDefault();
 120     },
 121
 122     /**
 123      * Called when the mouse has moved.
 124      */
 125     onMouseDragSizer_: function(event) {
 126       if (!this.mouseDragging_)
 127         return;
 128       // If dragging has started, move the sizer.
 129       this.onDragSizer_(event.pageX);
 130       event.preventDefault();
 131     },
 132
 133     /**
 134      * Called once the mouse has been released.
 135      */
 136     onMouseDragSizerEnd_: function(event) {
 137       if (!this.mouseDragging_)
 138         return;
 139       // Dragging is over.
 140       this.mouseDragging_ = false;
 141       event.preventDefault();
 142     },
 143
 144     /**
 145      * Called when the user touches the sizer.  Starts moving the sizer in
 146      * response to future touch events.
 147      */
 148     onTouchDragSizerStart_: function(event) {
 149       this.touchDragging_ = true;
 150       event.preventDefault();
 151     },
 152
 153     /**
 154      * Called when the mouse has moved after dragging started.
 155      */
 156     onTouchDragSizer_: function(event) {
 157       if (!this.touchDragging_)
 158         return;
 159       // If dragging has started, move the sizer.
 160       this.onDragSizer_(event.touches[0].pageX);
 161       event.preventDefault();
 162     },
 163
 164     /**
 165      * Called once the user stops touching the screen.
 166      */
 167     onTouchDragSizerEnd_: function(event) {
 168       if (!this.touchDragging_)
 169         return;
 170       // Dragging is over.
 171       this.touchDragging_ = false;
 172       event.preventDefault();
 173     },
 174
 175     /**
 176      * Common code used for both mouse and touch dragging.
 177      */
 178     onDragSizer_: function(pageX) {
 179       // Convert from page coordinates, to view coordinates.
 180       this.leftSplit_ = (pageX - this.getLeft());
 181
 182       // Avoid shrinking the left box too much.
 183       this.leftSplit_ = Math.max(this.leftSplit_, MIN_PANEL_WIDTH);
 184       // Avoid shrinking the right box too much.
 185       this.leftSplit_ = Math.min(
 186           this.leftSplit_, this.getWidth() - MIN_PANEL_WIDTH);
 187
 188       // Force a layout with the new |leftSplit_|.
 189       this.setGeometry(
 190           this.getLeft(), this.getTop(), this.getWidth(), this.getHeight());
 191     },
 192   };
 193
 194   return ResizableVerticalSplitView;
 195 })();