Merge branch 'smblott-link-hints-overlap' into post-1.46

2 files changed, 145 insertions, 29 deletions

diff --git a/lib/dom_utils.coffee b/lib/dom_utils.coffee
index 8db71001..ba5e279f 100644
--- a/lib/dom_utils.coffee
+++ b/lib/dom_utils.coffee
@@ -50,34 +50,7 @@ DomUtils =
   #
   getVisibleClientRect: (element) ->
     # Note: this call will be expensive if we modify the DOM in between calls.
-    clientRects = ({
-      top: clientRect.top, right: clientRect.right, bottom: clientRect.bottom, left: clientRect.left,
-      width: clientRect.width, height: clientRect.height
-    } for clientRect in element.getClientRects())
-
-    for clientRect in clientRects
-      if (clientRect.top < 0)
-        clientRect.height += clientRect.top
-        clientRect.top = 0
-
-      if (clientRect.left < 0)
-        clientRect.width += clientRect.left
-        clientRect.left = 0
-
-      if (clientRect.top >= window.innerHeight - 4 || clientRect.left  >= window.innerWidth - 4)
-        continue
-
-      if (clientRect.width < 3 || clientRect.height < 3)
-        continue
-
-      # eliminate invisible elements (see test_harnesses/visibility_test.html)
-      computedStyle = window.getComputedStyle(element, null)
-      if (computedStyle.getPropertyValue('visibility') != 'visible' ||
-          computedStyle.getPropertyValue('display') == 'none' ||
-          computedStyle.getPropertyValue('opacity') == '0')
-        continue
-
-      return clientRect
+    clientRects = (Rect.copy clientRect for clientRect in element.getClientRects())
 
     for clientRect in clientRects
       # If the link has zero dimensions, it may be wrapping visible
@@ -90,11 +63,72 @@ DomUtils =
           continue if (computedStyle.getPropertyValue('float') == 'none' &&
             computedStyle.getPropertyValue('position') != 'absolute')
           childClientRect = @getVisibleClientRect(child)
-          continue if (childClientRect == null)
+          continue if childClientRect == null or childClientRect.width < 3 or childClientRect.height < 3
           return childClientRect
+
+      else
+        clientRect = @cropRectToVisible clientRect
+
+        continue if clientRect == null or clientRect.width < 3 or clientRect.height < 3
+
+        # eliminate invisible elements (see test_harnesses/visibility_test.html)
+        computedStyle = window.getComputedStyle(element, null)
+        if (computedStyle.getPropertyValue('visibility') != 'visible' ||
+            computedStyle.getPropertyValue('display') == 'none')
+          continue
+
+        return clientRect
+
     null
 
   #
+  # Bounds the rect by the current viewport dimensions. If the rect is offscreen or has a height or width < 3
+  # then null is returned instead of a rect.
+  #
+  cropRectToVisible: (rect) ->
+    boundedRect = Rect.create(
+      Math.max(rect.left, 0)
+      Math.max(rect.top, 0)
+      rect.right
+      rect.bottom
+    )
+    if boundedRect.top >= window.innerHeight - 4 or boundedRect.left >= window.innerWidth - 4
+      null
+    else
+      boundedRect
+
+  #
+  # Get the client rects for the <area> elements in a <map> based on the position of the <img> element using
+  # the map. Returns an array of rects.
+  #
+  getClientRectsForAreas: (imgClientRect, areas) ->
+    rects = []
+    for area in areas
+      coords = area.coords.split(",").map((coord) -> parseInt(coord, 10))
+      shape = area.shape.toLowerCase()
+      if shape in ["rect", "rectangle"] # "rectangle" is an IE non-standard.
+        [x1, y1, x2, y2] = coords
+      else if shape in ["circle", "circ"] # "circ" is an IE non-standard.
+        [x, y, r] = coords
+        diff = r / Math.sqrt 2 # Gives us an inner square
+        x1 = x - diff
+        x2 = x + diff
+        y1 = y - diff
+        y2 = y + diff
+      else if shape == "default"
+        [x1, y1, x2, y2] = [0, 0, imgClientRect.width, imgClientRect.height]
+      else
+        # Just consider the rectangle surrounding the first two points in a polygon. It's possible to do
+        # something more sophisticated, but likely not worth the effort.
+        [x1, y1, x2, y2] = coords
+
+      rect = Rect.translate (Rect.create x1, y1, x2, y2), imgClientRect.left, imgClientRect.top
+      rect = @cropRectToVisible rect
+
+      rects.push {element: area, rect: rect} if rect and not isNaN rect.top
+    rects
+
+  #
   # Selectable means that we should use the simulateSelect method to activate the element instead of a click.
   #
   # The html5 input types that should use simulateSelect are:
diff --git a/lib/rect.coffee b/lib/rect.coffee
new file mode 100644
index 00000000..adc1fc36
--- /dev/null
+++ b/lib/rect.coffee
@@ -0,0 +1,82 @@
+# Commands for manipulating rects.
+Rect =
+  # Create a rect given the top left and bottom right corners.
+  create: (x1, y1, x2, y2) ->
+    bottom: y2
+    top: y1
+    left: x1
+    right: x2
+    width: x2 - x1
+    height: y2 - y1
+
+  copy: (rect) ->
+    bottom: rect.bottom
+    top: rect.top
+    left: rect.left
+    right: rect.right
+    width: rect.width
+    height: rect.height
+
+  # Translate a rect by x horizontally and y vertically.
+  translate: (rect, x = 0, y = 0) ->
+    bottom: rect.bottom + y
+    top: rect.top + y
+    left: rect.left + x
+    right: rect.right + x
+    width: rect.width
+    height: rect.height
+
+  # Subtract rect2 from rect1, returning an array of rects which are in rect1 but not rect2.
+  subtract: (rect1, rect2) ->
+    # Bound rect2 by rect1
+    rect2 = @create(
+      Math.max(rect1.left, rect2.left),
+      Math.max(rect1.top, rect2.top),
+      Math.min(rect1.right, rect2.right),
+      Math.min(rect1.bottom, rect2.bottom)
+    )
+
+    # If bounding rect2 has made the width or height negative, rect1 does not contain rect2.
+    return [Rect.copy rect1] if rect2.width < 0 or rect2.height < 0
+
+    #
+    # All the possible rects, in the order
+    # +-+-+-+
+    # |1|2|3|
+    # +-+-+-+
+    # |4| |5|
+    # +-+-+-+
+    # |6|7|8|
+    # +-+-+-+
+    # where the outer rectangle is rect1 and the inner rectangle is rect 2. Note that the rects may be of
+    # width or height 0.
+    #
+    rects = [
+      # Top row.
+      @create rect1.left, rect1.top, rect2.left, rect2.top
+      @create rect2.left, rect1.top, rect2.right, rect2.top
+      @create rect2.right, rect1.top, rect1.right, rect2.top
+      # Middle row.
+      @create rect1.left, rect2.top, rect2.left, rect2.bottom
+      @create rect2.right, rect2.top, rect1.right, rect2.bottom
+      # Bottom row.
+      @create rect1.left, rect2.bottom, rect2.left, rect1.bottom
+      @create rect2.left, rect2.bottom, rect2.right, rect1.bottom
+      @create rect2.right, rect2.bottom, rect1.right, rect1.bottom
+    ]
+
+    rects.filter (rect) -> rect.height > 0 and rect.width > 0
+
+  contains: (rect1, rect2) ->
+    rect1.right > rect2.left and
+    rect1.left < rect2.right and
+    rect1.bottom > rect2.top and
+    rect1.top < rect2.bottom
+
+  equals: (rect1, rect2) ->
+    for property in ["top", "bottom", "left", "right", "width", "height"]
+      return false if rect1[property] != rect2[property]
+    true
+
+root = exports ? window
+root.Rect = Rect