1
// Copyright 2006 The Closure Library Authors. All Rights Reserved.
2
//
3
// Licensed under the Apache License, Version 2.0 (the "License");
4
// you may not use this file except in compliance with the License.
5
// You may obtain a copy of the License at
6
//
7
//      http://www.apache.org/licenses/LICENSE-2.0
8
//
9
// Unless required by applicable law or agreed to in writing, software
10
// distributed under the License is distributed on an "AS-IS" BASIS,
11
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12
// See the License for the specific language governing permissions and
13
// limitations under the License.
14

15
/**
16
 * @fileoverview Client viewport positioning class.
17
 *
18
 * @author [email protected] (Robert Walker)
19
 * @author [email protected] (Emil A Eklund)
20
 */
21

22
goog.provide('goog.positioning.ViewportClientPosition');
23

24
goog.require('goog.dom');
25
goog.require('goog.math.Coordinate');
26
goog.require('goog.positioning');
27
goog.require('goog.positioning.ClientPosition');
28
goog.require('goog.positioning.Overflow');
29
goog.require('goog.positioning.OverflowStatus');
30
goog.require('goog.style');
31

32

33

34
/**
35
 * Encapsulates a popup position where the popup is positioned relative to the
36
 * window (client) coordinates, and made to stay within the viewport.
37
 *
38
 * @param {number|goog.math.Coordinate} arg1 Left position or coordinate.
39
 * @param {number=} opt_arg2 Top position if arg1 is a number representing the
40
 *     left position, ignored otherwise.
41
 * @constructor
42
 * @extends {goog.positioning.ClientPosition}
43
 */
44
goog.positioning.ViewportClientPosition = function(arg1, opt_arg2) {
45
  goog.positioning.ClientPosition.call(this, arg1, opt_arg2);
46
};
47
goog.inherits(
48
    goog.positioning.ViewportClientPosition, goog.positioning.ClientPosition);
49

50

51
/**
52
 * The last-resort overflow strategy, if the popup fails to fit.
53
 * @type {number}
54
 * @private
55
 */
56
goog.positioning.ViewportClientPosition.prototype.lastResortOverflow_ = 0;
57

58

59
/**
60
 * Set the last-resort overflow strategy, if the popup fails to fit.
61
 * @param {number} overflow A bitmask of goog.positioning.Overflow strategies.
62
 */
63
goog.positioning.ViewportClientPosition.prototype.setLastResortOverflow =
64
    function(overflow) {
65
  this.lastResortOverflow_ = overflow;
66
};
67

68

69
/**
70
 * Repositions the popup according to the current state.
71
 *
72
 * @param {Element} element The DOM element of the popup.
73
 * @param {goog.positioning.Corner} popupCorner The corner of the popup
74
 *     element that that should be positioned adjacent to the anchorElement.
75
 *     One of the goog.positioning.Corner constants.
76
 * @param {goog.math.Box=} opt_margin A margin specified in pixels.
77
 * @param {goog.math.Size=} opt_preferredSize Preferred size fo the element.
78
 * @override
79
 */
80
goog.positioning.ViewportClientPosition.prototype.reposition = function(
81
    element, popupCorner, opt_margin, opt_preferredSize) {
82
  var viewportElt = goog.style.getClientViewportElement(element);
83
  var viewport = goog.style.getVisibleRectForElement(viewportElt);
84
  var scrollEl = goog.dom.getDomHelper(element).getDocumentScrollElement();
85
  var clientPos = new goog.math.Coordinate(
86
      this.coordinate.x + scrollEl.scrollLeft,
87
      this.coordinate.y + scrollEl.scrollTop);
88

89
  var failXY =
90
      goog.positioning.Overflow.FAIL_X | goog.positioning.Overflow.FAIL_Y;
91
  var corner = popupCorner;
92

93
  // Try the requested position.
94
  var status = goog.positioning.positionAtCoordinate(
95
      clientPos, element, corner, opt_margin, viewport, failXY,
96
      opt_preferredSize);
97
  if ((status & goog.positioning.OverflowStatus.FAILED) == 0) {
98
    return;
99
  }
100

101
  // Outside left or right edge of viewport, try try to flip it horizontally.
102
  if (status & goog.positioning.OverflowStatus.FAILED_LEFT ||
103
      status & goog.positioning.OverflowStatus.FAILED_RIGHT) {
104
    corner = goog.positioning.flipCornerHorizontal(corner);
105
  }
106

107
  // Outside top or bottom edge of viewport, try try to flip it vertically.
108
  if (status & goog.positioning.OverflowStatus.FAILED_TOP ||
109
      status & goog.positioning.OverflowStatus.FAILED_BOTTOM) {
110
    corner = goog.positioning.flipCornerVertical(corner);
111
  }
112

113
  // Try flipped position.
114
  status = goog.positioning.positionAtCoordinate(
115
      clientPos, element, corner, opt_margin, viewport, failXY,
116
      opt_preferredSize);
117
  if ((status & goog.positioning.OverflowStatus.FAILED) == 0) {
118
    return;
119
  }
120

121
  // If that failed, the viewport is simply too small to contain the popup.
122
  // Revert to the original position.
123
  goog.positioning.positionAtCoordinate(
124
      clientPos, element, popupCorner, opt_margin, viewport,
125
      this.lastResortOverflow_, opt_preferredSize);
126
};
127

128