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// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.
using System;
using System.Windows.Automation;
using System.Windows.Automation.Provider;
using System.Runtime.InteropServices;
using System.Collections;
using System.ComponentModel;
using MS.Win32;
// PRESHARP: In order to avoid generating warnings about unkown message numbers and unknown pragmas.
#pragma warning disable 1634, 1691
namespace MS.Internal.AutomationProxies
{
static internal class ClickablePoint
{
/// <summary>
/// Static Constructor. Retrieve and keeps the hwnd for "Program"
/// The Windows Rectangle for "Program" is the union for the real
/// Estate for all the monitors.
/// </summary>
static ClickablePoint()
{
_hwndProgman = Misc.FindWindowEx(IntPtr.Zero, IntPtr.Zero, "Progman", null);
if (_hwndProgman == IntPtr.Zero)
{
_hwndProgman = _hwndDesktop;
}
}
//------------------------------------------------------
//
// Internal Methods
//
//------------------------------------------------------
#region Internal Methods
/// <summary>
/// Return a clickable point in a Rectangle for a given window
///
/// The algorithm uses the Windows Z order.
/// To be visible, a rectangle must be enclosed in the hwnd of its parents
/// and must but at least partially on top of the all of siblings as predecessors.
/// In the windows ordered scheme, the first sibling comes on top followed by the
/// next, etc. For a given hwnd, it is sufficent then to look for all the
/// predecessor siblings.
///
/// The scheme below is using recursion. This is make slightly harder to read
/// But makes it a bit more efficent.
/// </summary>
/// <param name="hwnd">Window Handle</param>
/// <param name="alIn">Input list of Rectangles to check GetPoint against</param>
/// <param name="alOut">Output list of Rectangles after the exclusion test</param>
/// <param name="pt">Clickable Point</param>
/// <returns>True if there is a clickable in ro</returns>
static internal bool GetPoint(IntPtr hwnd, ArrayList alIn, ArrayList alOut, ref NativeMethods.Win32Point pt)
{
IntPtr hwndStart = hwnd;
IntPtr hwndCurrent = hwnd;
// Do the window on top exclusion
// Only one level deep is necessary as grand children are clipped to their parent (our children)
for (hwnd = Misc.GetWindow(hwnd, NativeMethods.GW_CHILD); hwnd != IntPtr.Zero; hwnd = Misc.GetWindow(hwnd, NativeMethods.GW_HWNDNEXT))
{
// For siblings, the element bounding rectangle must not be covered by the
// bounding rect of its siblings
if (!ClickableInRect(hwnd, ref pt, true, alIn, alOut))
{
return false;
}
}
// Check for Parent and Sibling
hwnd = hwndStart;
while (true)
{
hwnd = Misc.GetWindow(hwnd, NativeMethods.GW_HWNDPREV);
if (hwnd == IntPtr.Zero)
{
// Very top of the Windows hierarchy we're done
if (hwndCurrent == _hwndDesktop)
{
break;
}
// The desktop is the parent we should stop here
if (Misc.IsBitSet(Misc.GetWindowStyle(hwndCurrent), NativeMethods.WS_POPUP))
{
hwnd = _hwndDesktop;
}
else
{
// We finished with all the hwnd siblings so get to the parent
hwnd = Misc.GetParent(hwndCurrent);
}
if (hwnd == IntPtr.Zero)
{
// final clipping against the desktop
hwnd = _hwndDesktop;
}
// For parent, the element bounding rectangle must be within it's parent bounding rect
// The desktop contains the bounding rectangle only for the main monintor, the
// The Progman window contains the area for the union of all the monitors
// Substitute the Desktop with the Progman hwnd for clipping calculation
IntPtr hwndClip = hwnd == _hwndDesktop ? _hwndProgman : hwnd;
if (!ClickableInRect(hwndClip, ref pt, false, alIn, alOut))
{
return false;
}
// Current Parent
hwndCurrent = hwnd;
continue;
}
// For siblings, the element bounding rectangle must not be covered by the
// bounding rect of its siblings
if (!ClickableInRect(hwnd, ref pt, true, alIn, alOut))
{
return false;
}
}
return true;
}
/// <summary>
/// Go through the list of all element chidren and exclude them from the list of
/// visible/clickable rectangles.
/// The element children may be listed in any order. A check on all of them must
/// be performed. There is no easy way out.
/// </summary>
/// <param name="fragment"></param>
/// <param name="alIn"></param>
/// <param name="alOut"></param>
internal static void ExcludeChildren(ProxyFragment fragment, ArrayList alIn, ArrayList alOut)
{
// First go through all the children to exclude whatever is on top
for (ProxySimple simple = fragment.GetFirstChild(); simple != null; simple = fragment.GetNextSibling(simple))
{
// The exclusion for hwnd children is done by the GetPoint routine
if (simple is ProxyHwnd)
{
continue;
}
// Copy the output bits
alIn.Clear();
alIn.AddRange(alOut);
NativeMethods.Win32Rect rc = new NativeMethods.Win32Rect(simple.BoundingRectangle);
CPRect rcp = new CPRect(ref rc, false);
ClickablePoint.SplitRect(alIn, ref rcp, alOut, true);
// recurse on the children
if (simple is ProxyFragment)
{
ExcludeChildren((ProxyFragment)simple, alIn, alOut);
}
}
}
#endregion
// ------------------------------------------------------
//
// Internal Fields
//
// ------------------------------------------------------
#region Internal Fields
/// <summary>
/// Rectangle is inclusive exclusive
/// </summary>
internal struct CPRect
{
internal bool _fNotCovered;
internal int _left;
internal int _top;
internal int _right;
internal int _bottom;
internal CPRect(int left, int top, int right, int bottom, bool fRiAsInsideRect)
{
_left = left;
_top = top;
_right = right;
_bottom = bottom;
_fNotCovered = fRiAsInsideRect;
}
// ref to make it a pointer
internal CPRect(ref NativeMethods.Win32Rect rc, bool fRiAsInsideRect)
{
_left = rc.left;
_top = rc.top;
_right = rc.right;
_bottom = rc.bottom;
_fNotCovered = fRiAsInsideRect;
}
// return true if the 2 rectangle intersects
internal bool Intersect(ref CPRect ri)
{
return !(_top >= ri._bottom || ri._top >= _bottom || _left >= ri._right || ri._left >= _right);
}
// return true if ri completely covers this
internal bool Overlap(ref CPRect ri)
{
return (ri._left <= _left && ri._right >= _right && ri._top <= _top && ri._bottom >= _bottom);
}
}
#endregion
// ------------------------------------------------------
//
// Private Methods
//
// ------------------------------------------------------
#region Private Methods
private static bool ClickableInRect(IntPtr hwnd, ref NativeMethods.Win32Point pt, bool fRiAsInsideRect, ArrayList alIn, ArrayList alOut)
{
if (!SafeNativeMethods.IsWindowVisible(hwnd))
{
return fRiAsInsideRect;
}
// Get the window rect. If this window has a width and it is effectivly invisible
NativeMethods.Win32Rect rc = new NativeMethods.Win32Rect();
if (!Misc.GetWindowRect(hwnd, ref rc))
{
return fRiAsInsideRect;
}
if ((rc.right - rc.left) <= 0 || (rc.bottom - rc.top) <= 0)
{
return fRiAsInsideRect;
}
// Try for transparency...
if (fRiAsInsideRect)
{
int x = (rc.right + rc.left) / 2;
int y = (rc.top + rc.bottom) / 2;
try
{
int lr = Misc.ProxySendMessageInt(hwnd, NativeMethods.WM_NCHITTEST, IntPtr.Zero, NativeMethods.Util.MAKELPARAM(x, y));
if (lr == NativeMethods.HTTRANSPARENT)
{
return true;
}
}
// PRESHARP: Warning - Catch statements should not have empty bodies
#pragma warning disable 6502
catch (TimeoutException)
{
// Ignore this timeout error. Avalon HwndWrappers have a problem with this WM_NCHITTEST call sometimes.
}
#pragma warning restore 6502
}
// Copy the output bits
alIn.Clear();
alIn.AddRange(alOut);
CPRect rcp = new CPRect(ref rc, false);
ClickablePoint.SplitRect(alIn, ref rcp, alOut, fRiAsInsideRect);
if (!GetClickablePoint(alOut, out pt.x, out pt.y))
{
return false;
}
return true;
}
/// <summary>
/// Split a rectangle into a maximum of 3 rectangble.
/// ro is the outside rectangle and ri is the inside rectangle
/// ro might is split vertically in a a maximim of 3 rectangles sharing the same
/// right and left margin
/// </summary>
/// <param name="ro">Outside Rectangle</param>
/// <param name="ri">Inside Rectangle</param>
/// <param name="left">Left Margin for the resulting rectangles</param>
/// <param name="right">Right Margin for the resulting rectangles</param>
/// <param name="alRect">Array of resulting rectangles</param>
/// <param name="fRiAsInsideRect">Covered flag</param>
static private void SplitVertical(ref CPRect ro, ref CPRect ri, int left, int right, ArrayList alRect, bool fRiAsInsideRect)
{
// bottom clip
if (ri._bottom > ro._bottom)
{
ri._bottom = ro._bottom;
}
int top = ro._top;
int bottom = ri._top;
if (bottom > top)
{
alRect.Add(new CPRect(left, top, right, bottom, ro._fNotCovered));
top = bottom;
}
bottom = ri._bottom;
if (bottom > top)
{
alRect.Add(new CPRect(left, top, right, bottom, ro._fNotCovered & fRiAsInsideRect));
top = bottom;
}
bottom = ro._bottom;
if (bottom > top)
{
alRect.Add(new CPRect(left, top, right, bottom, ro._fNotCovered));
}
}
/// <summary>
/// Slip a rectangle into a maximum of 5 pieces.
/// ro is the out rectangle and ri is the exclusion rectangle.
/// The number of resulting rectangles varies based on the position of ri relative to ro
/// Each resulting reactangles are flaged as covered or not.
/// The ro covered flag is or'ed to allow for recursive calls
///
/// +-----------------+
/// | : 2 : |
/// | : : |
/// | ###### |
/// | ###3## |
/// | 1 ###### 5 |
/// | ###### |
/// | : : |
/// | : 4 : |
/// | : : |
/// +-----------------+
/// </summary>
/// <param name="ro">Outside Rectangle</param>
/// <param name="ri">Inside Rectangle</param>
/// <param name="alRect">Collection of resulting rectangles</param>
/// <param name="fRiAsInsideRect"></param>
static private void SplitRect(ref CPRect ro, CPRect ri, ArrayList alRect, bool fRiAsInsideRect)
{
// If ri is fully outside easy way out.
if (!ro._fNotCovered || !ro.Intersect(ref ri))
{
ro._fNotCovered &= fRiAsInsideRect;
alRect.Add(ro);
return;
}
if (ro.Overlap(ref ri))
{
ro._fNotCovered &= !fRiAsInsideRect;
alRect.Add(ro);
return;
}
// right clip
if (ri._right > ro._right)
{
ri._right = ro._right;
}
// bottom clip
if (ri._bottom > ro._bottom)
{
ri._bottom = ro._bottom;
}
int left = ro._left;
int right = ri._left;
if (right > left)
{
alRect.Add(new CPRect(left, ro._top, right, ro._bottom, ro._fNotCovered & fRiAsInsideRect));
left = right;
}
right = ri._right;
if (right > left)
{
SplitVertical(ref ro, ref ri, left, right, alRect, !fRiAsInsideRect);
left = right;
}
right = ro._right;
if (right > left)
{
alRect.Add(new CPRect(left, ro._top, right, ro._bottom, ro._fNotCovered & fRiAsInsideRect));
}
}
/// <summary>
/// Takes as input a set of rectangles to perform a rectangular decomposition
/// based on the ri. It creates a new set of rectangles each of them being
/// marked as covered or not.
///
/// </summary>
/// <param name="alIn">List of input rectangle</param>
/// <param name="ri">Overlapping Rectangle</param>
/// <param name="alOut">New sets of reactangle</param>
/// <param name="fRiAsInsideRect">Input Rectangle is rectangle covering alIn Rects or everything
/// outside of ri must be marked as covered</param>
static private void SplitRect(ArrayList alIn, ref CPRect ri, ArrayList alOut, bool fRiAsInsideRect)
{
alOut.Clear();
for (int i = 0, c = alIn.Count; i < c; i++)
{
CPRect ro = (CPRect)alIn[i];
SplitRect(ref ro, ri, alOut, fRiAsInsideRect);
}
}
/// <summary>
/// Find a clickable point in a list of rectangle.
/// Goes through the list of rectangle, stops on the first rectangle that is not covered
/// and returns the mid point
/// </summary>
/// <param name="al">list of ractangle</param>
/// <param name="x">X coordinate for a clickable point</param>
/// <param name="y">Y coordinate for a clickable point</param>
/// <returns>Clickable point found</returns>
static private bool GetClickablePoint(ArrayList al, out int x, out int y)
{
for (int i = 0, c = al.Count; i < c; i++)
{
CPRect r = (CPRect)al[i];
if (r._fNotCovered == true && (r._right - r._left) * (r._bottom - r._top) > 0)
{
// Skip if the rectangle is empty
if (r._right > r._left && r._bottom > r._top)
{
// mid point rounded to the left
x = ((r._right - 1) + r._left) / 2;
y = ((r._bottom - 1) + r._top) / 2;
return true;
}
}
}
x = y = 0;
return false;
}
#endregion
#region Private fields
// Top level Desktop window
private static IntPtr _hwndDesktop = UnsafeNativeMethods.GetDesktopWindow();
/// The WindowsRect for "Program" is the union for the real
/// estate for all the monitors. Instead of doing clipping against the root of the hwnd
/// tree that is the desktop. The last clipping should be done against the Progman hwnd.
private static IntPtr _hwndProgman;
#endregion Private fields
}
}
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