[reactos] 01/01: [EXPLORER] 'Show Desktop' button should work on button up (#4718)

[Katayama Hirofumi MZ]

https://git.reactos.org/?p=reactos.git;a=commitdiff;h=ba2cead8a2494f7c1bf36…

commit ba2cead8a2494f7c1bf366d4a1a0f66ab96316d1
Author:     Katayama Hirofumi MZ <katayama.hirofumi.mz(a)gmail.com>
AuthorDate: Thu Sep 22 23:01:12 2022 +0900
Commit:     GitHub <noreply(a)github.com>
CommitDate: Thu Sep 22 23:01:12 2022 +0900

    [EXPLORER] 'Show Desktop' button should work on button up (#4718)
    
    Follow-up of PR #4715. CORE-15369
    - The 'Show Desktop' button of taskbar works on button up instead of button
down.
    - Add NULL checks for m_ShowDesktopButton.
    - Fix hung-up in rebooting.
---
 base/shell/explorer/traywnd.cpp | 20 ++++++++++++--------
 1 file changed, 12 insertions(+), 8 deletions(-)

diff --git a/base/shell/explorer/traywnd.cpp b/base/shell/explorer/traywnd.cpp
index f1ff6242182..b3384a4dc06 100644
--- a/base/shell/explorer/traywnd.cpp
+++ b/base/shell/explorer/traywnd.cpp
@@ -310,7 +310,7 @@ public:
             return 0;
 
         // Show/Hide Desktop
-        ::SendMessageW(::GetParent(m_hWnd), WM_COMMAND, TRAYCMD_TOGGLE_DESKTOP, 0);
+        GetParent().SendMessage(WM_COMMAND, TRAYCMD_TOGGLE_DESKTOP, 0);
         return 0;
     }
 
@@ -324,7 +324,7 @@ public:
         PostMessage(TSDB_CLICK, 0, 0);
     }
 
-    LRESULT OnLButtonDown(UINT uMsg, WPARAM wParam, LPARAM lParam, BOOL& bHandled)
+    LRESULT OnLButtonUp(UINT uMsg, WPARAM wParam, LPARAM lParam, BOOL& bHandled)
     {
         Click(); // Left-click
         return 0;
@@ -357,6 +357,8 @@ public:
 
     BOOL PtInButton(POINT pt)
     {
+        if (!IsWindow())
+            return FALSE;
         RECT rc;
         GetWindowRect(&rc);
         INT cxEdge = ::GetSystemMetrics(SM_CXEDGE), cyEdge =
::GetSystemMetrics(SM_CYEDGE);
@@ -375,7 +377,7 @@ public:
         m_bHovering = TRUE;
         SetTimer(SHOW_DESKTOP_TIMER_ID, SHOW_DESKTOP_TIMER_INTERVAL, NULL);
         InvalidateRect(NULL, TRUE);
-        ::SendMessageW(::GetParent(m_hWnd), WM_NCPAINT, 0, 0);
+        GetParent().PostMessage(WM_NCPAINT, 0, 0);
     }
 
     LRESULT OnMouseMove(UINT uMsg, WPARAM wParam, LPARAM lParam, BOOL& bHandled)
@@ -396,7 +398,7 @@ public:
             m_bHovering = FALSE;
             KillTimer(SHOW_DESKTOP_TIMER_ID);
             InvalidateRect(NULL, TRUE);
-            ::SendMessageW(::GetParent(m_hWnd), WM_NCPAINT, 0, 0);
+            GetParent().PostMessage(WM_NCPAINT, 0, 0);
         }
 
         return 0;
@@ -413,7 +415,7 @@ public:
     }
 
     BEGIN_MSG_MAP(CTrayShowDesktopButton)
-        MESSAGE_HANDLER(WM_LBUTTONDOWN, OnLButtonDown)
+        MESSAGE_HANDLER(WM_LBUTTONUP, OnLButtonUp)
         MESSAGE_HANDLER(WM_SETTINGCHANGE, OnSettingChanged)
         MESSAGE_HANDLER(WM_THEMECHANGED, OnSettingChanged)
         MESSAGE_HANDLER(WM_PAINT, OnPaint)
@@ -2605,13 +2607,15 @@ ChangePos:
     // We have to draw non-client area because the 'Show Desktop' button is
beyond client area.
     void DrawShowDesktopButton()
     {
+        if (!m_ShowDesktopButton.IsWindow())
+            return;
         // Get the rectangle in window coordinates
         RECT rcButton, rcWnd;
         GetWindowRect(&rcWnd);
         m_ShowDesktopButton.GetWindowRect(&rcButton);
         ::OffsetRect(&rcButton, -rcWnd.left, -rcWnd.top);
 
-        HDC hdc = GetDCEx(NULL, DCX_WINDOW | DCX_CACHE | DCX_NORESETATTRS);
+        HDC hdc = GetDCEx(NULL, DCX_WINDOW | DCX_CACHE);
         m_ShowDesktopButton.OnDraw(hdc, &rcButton); // Draw the button
         ReleaseDC(hdc);
     }
@@ -3232,10 +3236,10 @@ HandleTrayContextMenu:
 
     LRESULT OnNcActivate(UINT uMsg, WPARAM wParam, LPARAM lParam, BOOL& bHandled)
     {
-        DefWindowProc(uMsg, wParam, lParam);
+        LRESULT ret = DefWindowProc(uMsg, wParam, lParam);
         DrawShowDesktopButton(); // We have to draw non-client area
         bHandled = TRUE;
-        return 0;
+        return ret;
     }
 
     LRESULT OnNcCalcSize(INT code, WPARAM wParam, LPARAM lParam, BOOL& bHandled)