Add ability for ThemeCreateParentWindow to center on the monitor.

4 files changed, 108 insertions, 1 deletions

diff --git a/src/dutil/dpiutil.cpp b/src/dutil/dpiutil.cpp
index edab8f01..a27ee8c5 100644
--- a/src/dutil/dpiutil.cpp
+++ b/src/dutil/dpiutil.cpp
@@ -62,6 +62,59 @@ DAPI_(void) DpiuUninitialize()
     vfDpiuInitialized = FALSE;
 }
 
+DAPI_(HRESULT) DpiuGetMonitorContextFromPoint(
+    __in const POINT* pt,
+    __out DPIU_MONITOR_CONTEXT** ppMonitorContext
+    )
+{
+    HRESULT hr = S_OK;
+    DPIU_MONITOR_CONTEXT* pMonitorContext = NULL;
+    HMONITOR hMonitor = NULL;
+    UINT dpiX = 0;
+    UINT dpiY = 0;
+    HDC hdc = NULL;
+
+    pMonitorContext = reinterpret_cast<DPIU_MONITOR_CONTEXT*>(MemAlloc(sizeof(DPIU_MONITOR_CONTEXT), TRUE));
+    DpiuExitOnNull(pMonitorContext, hr, E_OUTOFMEMORY, "Failed to allocate memory for DpiuMonitorContext.");
+
+    hMonitor = ::MonitorFromPoint(*pt, MONITOR_DEFAULTTONEAREST);
+    DpiuExitOnNull(hMonitor, hr, E_FAIL, "Failed to get monitor from point.");
+
+    pMonitorContext->mi.cbSize = sizeof(pMonitorContext->mi);
+    if (!::GetMonitorInfoW(hMonitor, &pMonitorContext->mi))
+    {
+        DpiuExitOnFailure(hr = E_OUTOFMEMORY, "Failed to get monitor info for point.");
+    }
+
+    if (vpfnGetDpiForMonitor)
+    {
+        hr = vpfnGetDpiForMonitor(hMonitor, MDT_EFFECTIVE_DPI, &dpiX, &dpiY);
+        DpiuExitOnFailure(hr, "Failed to get DPI for monitor.");
+
+        pMonitorContext->nDpi = dpiX;
+    }
+    else
+    {
+        hdc = ::CreateDCW(L"DISPLAY", pMonitorContext->mi.szDevice, NULL, NULL);
+        DpiuExitOnNull(hdc, hr, E_OUTOFMEMORY, "Failed to get device context for monitor.");
+
+        pMonitorContext->nDpi = ::GetDeviceCaps(hdc, LOGPIXELSX);
+    }
+
+    *ppMonitorContext = pMonitorContext;
+    pMonitorContext = NULL;
+
+LExit:
+    if (hdc)
+    {
+        ::ReleaseDC(NULL, hdc);
+    }
+
+    MemFree(pMonitorContext);
+
+    return hr;
+}
+
 DAPI_(void) DpiuGetWindowContext(
     __in HWND hWnd,
     __in DPIU_WINDOW_CONTEXT* pWindowContext
diff --git a/src/dutil/inc/dpiutil.h b/src/dutil/inc/dpiutil.h
index c6f73b02..8c61ab19 100644
--- a/src/dutil/inc/dpiutil.h
+++ b/src/dutil/inc/dpiutil.h
@@ -14,6 +14,12 @@ extern "C" {
 #define USER_DEFAULT_SCREEN_DPI 96
 #endif
 
+typedef struct _DPIU_MONITOR_CONTEXT
+{
+    UINT nDpi;
+    MONITORINFOEXW mi;
+} DPIU_MONITOR_CONTEXT;
+
 typedef struct _DPIU_WINDOW_CONTEXT
 {
     UINT nDpi;
@@ -33,6 +39,15 @@ void DAPI DpiuInitialize();
 void DAPI DpiuUninitialize();
 
 /********************************************************************
+ DpiuGetMonitorContextFromPoint - get the DPI context of the monitor from the given point.
+
+*******************************************************************/
+HRESULT DAPI DpiuGetMonitorContextFromPoint(
+    __in const POINT* pt,
+    __out DPIU_MONITOR_CONTEXT** ppMonitorContext
+    );
+
+/********************************************************************
  DpiuGetWindowContext - get the DPI context of the given window.
 
 *******************************************************************/
diff --git a/src/dutil/inc/thmutil.h b/src/dutil/inc/thmutil.h
index c75f9587..1ba5db35 100644
--- a/src/dutil/inc/thmutil.h
+++ b/src/dutil/inc/thmutil.h
@@ -81,6 +81,12 @@ typedef enum THEME_SHOW_PAGE_REASON
     THEME_SHOW_PAGE_REASON_REFRESH,
 } THEME_SHOW_PAGE_REASON;
 
+typedef enum THEME_WINDOW_INITIAL_POSITION
+{
+    THEME_WINDOW_INITIAL_POSITION_DEFAULT,
+    THEME_WINDOW_INITIAL_POSITION_CENTER_MONITOR_FROM_COORDINATES,
+} THEME_WINDOW_INITIAL_POSITION;
+
 
 struct THEME_COLUMN
 {
@@ -394,6 +400,7 @@ HRESULT DAPI ThemeCreateParentWindow(
     __in_opt HWND hwndParent,
     __in_opt HINSTANCE hInstance,
     __in_opt LPVOID lpParam,
+    __in THEME_WINDOW_INITIAL_POSITION initialPosition,
     __out_opt HWND* phWnd
     );
 
diff --git a/src/dutil/thmutil.cpp b/src/dutil/thmutil.cpp
index 4da489e4..a1b101e8 100644
--- a/src/dutil/thmutil.cpp
+++ b/src/dutil/thmutil.cpp
@@ -603,10 +603,14 @@ DAPI_(HRESULT) ThemeCreateParentWindow(
     __in_opt HWND hwndParent,
     __in_opt HINSTANCE hInstance,
     __in_opt LPVOID lpParam,
+    __in THEME_WINDOW_INITIAL_POSITION initialPosition,
     __out_opt HWND* phWnd
     )
 {
     HRESULT hr = S_OK;
+    DPIU_MONITOR_CONTEXT* pMonitorContext = NULL;
+    POINT pt = { };
+    RECT* pMonitorRect = NULL;
     HWND hWnd = NULL;
 
     if (pTheme->hwndParent)
@@ -614,6 +618,29 @@ DAPI_(HRESULT) ThemeCreateParentWindow(
         ThmExitOnFailure(hr = E_INVALIDSTATE, "ThemeCreateParentWindow called after the theme was loaded.");
     }
 
+    if (THEME_WINDOW_INITIAL_POSITION_CENTER_MONITOR_FROM_COORDINATES == initialPosition)
+    {
+        pt.x = x;
+        pt.y = y;
+        hr = DpiuGetMonitorContextFromPoint(&pt, &pMonitorContext);
+        if (SUCCEEDED(hr))
+        {
+            pMonitorRect = &pMonitorContext->mi.rcWork;
+            if (pMonitorContext->nDpi != pTheme->nDpi)
+            {
+                ScaleTheme(pTheme, pMonitorContext->nDpi, pMonitorRect->left, pMonitorRect->top);
+            }
+
+            x = pMonitorRect->left + (pMonitorRect->right - pMonitorRect->left - pTheme->nWidth) / 2;
+            y = pMonitorRect->top + (pMonitorRect->bottom - pMonitorRect->top - pTheme->nHeight) / 2;
+        }
+        else
+        {
+            x = CW_USEDEFAULT;
+            y = CW_USEDEFAULT;
+        }
+    }
+
     hWnd = ::CreateWindowExW(dwExStyle, szClassName, szWindowName, dwStyle, x, y, pTheme->nWidth, pTheme->nHeight, hwndParent, NULL, hInstance, lpParam);
     ThmExitOnNullWithLastError(hWnd, hr, "Failed to create theme parent window.");
     ThmExitOnNull(pTheme->hwndParent, hr, E_INVALIDSTATE, "Theme parent window is not set, make sure ThemeDefWindowProc is called for WM_NCCREATE.");
@@ -625,6 +652,8 @@ DAPI_(HRESULT) ThemeCreateParentWindow(
     }
 
 LExit:
+    MemFree(pMonitorContext);
+
     return hr;
 }
 
@@ -5471,7 +5500,10 @@ static void ScaleTheme(
 
     ScaleControls(pTheme, pTheme->cControls, pTheme->rgControls, pTheme->nDpi);
 
-    ::SetWindowPos(pTheme->hwndParent, NULL, x, y, pTheme->nWidth, pTheme->nHeight, SWP_NOACTIVATE | SWP_NOZORDER);
+    if (pTheme->hwndParent)
+    {
+        ::SetWindowPos(pTheme->hwndParent, NULL, x, y, pTheme->nWidth, pTheme->nHeight, SWP_NOACTIVATE | SWP_NOZORDER);
+    }
 }
 
 static void ScaleControls(