changed DPI handling: dpi is now pushed into every control and saved there

1 files changed, 94 insertions, 59 deletions

diff --git a/alf/alfcombobox.cpp b/alf/alfcombobox.cpp
index 6d3af5e..994806e 100644
--- a/alf/alfcombobox.cpp
+++ b/alf/alfcombobox.cpp
@@ -17,6 +17,38 @@ typedef struct {
     DWORD  comboStyle;
 } ALFComboCreateParams;
 
+typedef struct {
+    HWND hwndChild;
+    int  dpi;
+} ALFComboPriv;
+
+static ALFComboPriv *
+ALF_Combo_InitializePriv(HWND hwnd, ALFComboCreateParams *params)
+{
+    ALFComboPriv *priv = ALF_New(ALFComboPriv, 1);
+    priv->dpi = 96;
+
+    DWORD comboStyle = params->comboStyle | CBS_OWNERDRAWFIXED | CBS_HASSTRINGS;
+
+    priv->hwndChild = CreateWindowEx(0,
+                                     TEXT("COMBOBOX"),
+                                     TEXT(""),
+                                     WS_CHILD | WS_VISIBLE | WS_VSCROLL | WS_TABSTOP | comboStyle,
+                                     0, 0, 100, 200 /* FIXME needed for commctl32 v5, what is the best value here? */,
+                                     hwnd,
+                                     (HMENU) GetWindowLongPtrW(hwnd, GWLP_ID),
+                                     ALF_HINSTANCE,
+                                     NULL);
+
+    return priv;
+}
+
+static void
+ALF_Combo_FreePriv(ALFComboPriv *priv)
+{
+    ALF_Free(priv);
+}
+
 static int
 ALF__ComboItemHeight(HWND hwnd)
 {
@@ -48,83 +80,80 @@ ALF__ComboItemHeight(HWND hwnd)
 static LRESULT CALLBACK
 ALF__ComboWindowProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
 {
-    HWND   hwndChild = (HWND)GetWindowLongPtr(hwnd, 0);
+    ALFComboPriv *priv = (ALFComboPriv *)GetWindowLongPtr(hwnd, 0);
 
     if (uMsg == WM_CREATE) {
         ALFComboCreateParams *params = (ALFComboCreateParams*)((CREATESTRUCT*)lParam)->lpCreateParams;
-        DWORD comboStyle = params->comboStyle | CBS_OWNERDRAWFIXED | CBS_HASSTRINGS;
-
-        HWND hwndCombo = CreateWindowEx(0,
-                                        TEXT("COMBOBOX"),
-                                        TEXT(""),
-                                        WS_CHILD | WS_VISIBLE | WS_VSCROLL | WS_TABSTOP | comboStyle,
-                                        0, 0, 100, 200 /* FIXME needed for commctl32 v5, what is the best value here? */,
-                                        hwnd,
-                                        (HMENU) GetWindowLongPtrW(hwnd, GWLP_ID),
-                                        ((CREATESTRUCT*)lParam)->hInstance,
-                                        NULL);
-
-        SetWindowLongPtr(hwnd, 0, (LONG_PTR)hwndCombo);
+
+        priv = ALF_Combo_InitializePriv(hwnd, params);
+        SetWindowLongPtr(hwnd, 0, (LONG_PTR)priv);
+    }
+
+    if (uMsg == WM_DESTROY) {
+        ALF_Combo_FreePriv(priv);
+        priv = NULL;
+        SetWindowLongPtr(hwnd, 0, 0);
     }
-    if (uMsg == WM_ENABLE && hwndChild) {
-        EnableWindow(hwndChild, (BOOL)wParam);
+
+    if (uMsg == WM_ENABLE && priv) {
+        EnableWindow(priv->hwndChild, (BOOL)wParam);
         return 0;
     }
-    if (uMsg == WM_SETTEXT && hwndChild) {
-        SetWindowText(hwndChild, (TCHAR*)lParam);
+    if (uMsg == WM_SETTEXT && priv) {
+        SetWindowText(priv->hwndChild, (TCHAR*)lParam);
         ALF_InvalidateLayout(GetParent(hwnd));
     }
-    if (uMsg == WM_GETTEXTLENGTH && hwndChild) {
-        return (LRESULT)GetWindowTextLength(hwndChild);
+    if (uMsg == WM_GETTEXTLENGTH && priv) {
+        return (LRESULT)GetWindowTextLength(priv->hwndChild);
     }
-    if (uMsg == WM_GETTEXT && hwndChild) {
-        return GetWindowText(hwndChild, (TCHAR*)lParam, (int)wParam);
+    if (uMsg == WM_GETTEXT && priv) {
+        return GetWindowText(priv->hwndChild, (TCHAR*)lParam, (int)wParam);
     }
-    if (uMsg == WM_SETFONT && hwndChild) {
-        SendMessage(hwndChild, WM_SETFONT, wParam, lParam);
-        SendMessage(hwndChild, CB_SETITEMHEIGHT, (WPARAM)0, (LPARAM)ALF__ComboItemHeight(hwnd));
+    if (uMsg == WM_SETFONT && priv) {
+        SendMessage(priv->hwndChild, WM_SETFONT, wParam, lParam);
+        SendMessage(priv->hwndChild, CB_SETITEMHEIGHT, (WPARAM)0, (LPARAM)ALF__ComboItemHeight(hwnd));
 
         ALF_InvalidateLayout(GetParent(hwnd));
 
         return 0;
     }
-    if (uMsg == WM_GETFONT && hwndChild) {
-        return SendMessage(hwndChild, WM_GETFONT, wParam, lParam);
+    if (uMsg == WM_GETFONT && priv) {
+        return SendMessage(priv->hwndChild, WM_GETFONT, wParam, lParam);
     }
-    if (uMsg == ALF_CB_GETSTYLE && hwndChild) {
-        return GetWindowLong(hwndChild, GWL_STYLE);
+    if (uMsg == ALF_CB_GETSTYLE && priv) {
+        return GetWindowLong(priv->hwndChild, GWL_STYLE);
     }
-    if ((uMsg == ALF_CB_FINDSTRINGEXACT || uMsg == CB_FINDSTRINGEXACT) && hwndChild) {
-        return SendMessage(hwndChild, CB_FINDSTRINGEXACT, wParam, lParam);
+    if ((uMsg == ALF_CB_FINDSTRINGEXACT || uMsg == CB_FINDSTRINGEXACT) && priv) {
+        return SendMessage(priv->hwndChild, CB_FINDSTRINGEXACT, wParam, lParam);
     }
-    if ((uMsg == ALF_CB_ADDSTRING || uMsg == CB_ADDSTRING) && hwndChild) {
-        return SendMessage(hwndChild, CB_ADDSTRING, wParam, lParam);
+    if ((uMsg == ALF_CB_ADDSTRING || uMsg == CB_ADDSTRING) && priv) {
+        return SendMessage(priv->hwndChild, CB_ADDSTRING, wParam, lParam);
     }
-    if ((uMsg == ALF_CB_INSERTSTRING || uMsg == CB_INSERTSTRING) && hwndChild) {
-        return SendMessage(hwndChild, CB_INSERTSTRING, wParam, lParam);
+    if ((uMsg == ALF_CB_INSERTSTRING || uMsg == CB_INSERTSTRING) && priv) {
+        return SendMessage(priv->hwndChild, CB_INSERTSTRING, wParam, lParam);
     }
-    if ((uMsg == ALF_CB_DELETESTRING || uMsg == CB_DELETESTRING) && hwndChild) {
-        return SendMessage(hwndChild, CB_DELETESTRING, wParam, lParam);
+    if ((uMsg == ALF_CB_DELETESTRING || uMsg == CB_DELETESTRING) && priv) {
+        return SendMessage(priv->hwndChild, CB_DELETESTRING, wParam, lParam);
     }
-    if ((uMsg == ALF_CB_GETCURSEL || uMsg == CB_GETCURSEL) && hwndChild) {
-        return SendMessage(hwndChild, CB_GETCURSEL, wParam, lParam);
+    if ((uMsg == ALF_CB_GETCURSEL || uMsg == CB_GETCURSEL) && priv) {
+        return SendMessage(priv->hwndChild, CB_GETCURSEL, wParam, lParam);
     }
-    if ((uMsg == ALF_CB_SETCURSEL || uMsg == CB_SETCURSEL) && hwndChild) {
-        LRESULT curSel = SendMessage(hwndChild, CB_GETCURSEL, 0, 0);
+    if ((uMsg == ALF_CB_SETCURSEL || uMsg == CB_SETCURSEL) && priv) {
+        LRESULT curSel = SendMessage(priv->hwndChild, CB_GETCURSEL, 0, 0);
         if ((WPARAM)curSel != wParam) {
-            LRESULT newSel = SendMessage(hwndChild, CB_SETCURSEL, wParam, 0);
-            SendMessage(hwnd, WM_COMMAND, MAKEWPARAM(GetWindowLong(hwndChild, GWL_ID), CBN_SELCHANGE), (LPARAM)hwndChild);
+            LRESULT newSel = SendMessage(priv->hwndChild, CB_SETCURSEL, wParam, 0);
+            SendMessage(hwnd, WM_COMMAND, MAKEWPARAM(GetWindowLong(priv->hwndChild, GWL_ID), CBN_SELCHANGE), (LPARAM)priv->hwndChild);
             return newSel;
         }
     }
-    if ((uMsg == ALF_CB_GETLBTEXTLEN || uMsg == CB_GETLBTEXTLEN) && hwndChild) {
-        return SendMessage(hwndChild, CB_GETLBTEXTLEN, wParam, lParam);
+    if ((uMsg == ALF_CB_GETLBTEXTLEN || uMsg == CB_GETLBTEXTLEN) && priv) {
+        return SendMessage(priv->hwndChild, CB_GETLBTEXTLEN, wParam, lParam);
     }
-    if ((uMsg == ALF_CB_GETLBTEXT || uMsg == CB_GETLBTEXT) && hwndChild) {
-        return SendMessage(hwndChild, CB_GETLBTEXT, wParam, lParam);
+    if ((uMsg == ALF_CB_GETLBTEXT || uMsg == CB_GETLBTEXT) && priv) {
+        return SendMessage(priv->hwndChild, CB_GETLBTEXT, wParam, lParam);
     }
 
-    if (uMsg == WM_COMMAND && (HWND)lParam == hwndChild) {
+    if (uMsg == WM_COMMAND && priv && (HWND)lParam == priv->hwndChild) {
         // XXX: for whatever reason, Win95 (and only win95 - doesn't happen on NT)
         // sends a wrong ID value in WPARAM. We fix it by replacing it with our own id.
         return SendMessage(GetParent(hwnd), WM_COMMAND, MAKEWPARAM(GetWindowLong(hwnd, GWL_ID), HIWORD(wParam)), (LPARAM)hwnd);
@@ -143,12 +172,12 @@ ALF__ComboWindowProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
             if (GetTextMetrics(hDc, &tm)) {
                 SIZE *ps = (SIZE*)lParam;
                 if (!ps->cx) {
-                    ps->cx = ALF_CentipointsToPixels(GetParent(hwnd), 12000);
+                    ps->cx = ALF_CentipointsToPixels(12000, priv->dpi);
                 }
 
                 if (!ps->cy) {
                     ps->cy = tm.tmHeight + 2*ALF_Compat_GetSystemMetricsForDpi(
-                            SM_CYEDGE, (UINT)ALF_CentipointsToPixels(GetParent(hwnd), 7200))
+                            SM_CYEDGE, (UINT)priv->dpi)
                         + 4 /* padding internal to the edit control */;
                 }
             }
@@ -225,30 +254,36 @@ ALF__ComboWindowProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
         return TRUE;
     }
 
-    if (uMsg == WM_WINDOWPOSCHANGED && hwndChild) {
+    if (uMsg == WM_WINDOWPOSCHANGED && priv) {
         WINDOWPOS *pos = (WINDOWPOS *)lParam;
         if (!(pos->flags & SWP_NOSIZE)) {
             // XXX: When resizing the combo box, it will improperly draw a selection.
             // this appears to be a well-known bug that is still not fixed, even in Win10.
             // workaround based on https://stackoverflow.com/questions/49603893/how-to-deal-with-invalidly-painted-combobox-control-in-win32-winapi
-            LRESULT sel = SendMessage(hwndChild, CB_GETEDITSEL, 0, 0);
-            SendMessage(hwndChild, CB_SETEDITSEL, 0, -1);
+            LRESULT sel = SendMessage(priv->hwndChild, CB_GETEDITSEL, 0, 0);
+            SendMessage(priv->hwndChild, CB_SETEDITSEL, 0, -1);
             // SWP_NOCOPYBITS because NT 3.51 doesn't properly repaint the drop-down button
-            SetWindowPos(hwndChild, NULL, 0, 0, pos->cx, 200, SWP_NOZORDER|SWP_NOACTIVATE|SWP_NOCOPYBITS);
-            SendMessage(hwndChild, CB_SETEDITSEL, 0, (LPARAM)sel);
+            SetWindowPos(priv->hwndChild, NULL, 0, 0, pos->cx, 200, SWP_NOZORDER|SWP_NOACTIVATE|SWP_NOCOPYBITS);
+            SendMessage(priv->hwndChild, CB_SETEDITSEL, 0, (LPARAM)sel);
 
             int heightOffset = 0;
             if (ALF_Compat_IsMinWindowsVersion(4, 0)) {
                 heightOffset = - 2*ALF_Compat_GetSystemMetricsForDpi(
-                            SM_CYEDGE, (UINT)ALF_CentipointsToPixels(GetParent(hwnd), 7200))
+                            SM_CYEDGE, (UINT)priv->dpi)
                             - 2;
             }
 
-            SendMessage(hwndChild, CB_SETITEMHEIGHT, (WPARAM)-1, pos->cy + heightOffset);
-            SendMessage(hwndChild, CB_SETITEMHEIGHT, (WPARAM)0, (LPARAM)ALF__ComboItemHeight(hwnd));
+            SendMessage(priv->hwndChild, CB_SETITEMHEIGHT, (WPARAM)-1, pos->cy + heightOffset);
+            SendMessage(priv->hwndChild, CB_SETITEMHEIGHT, (WPARAM)0, (LPARAM)ALF__ComboItemHeight(hwnd));
         }
     }
 
+    if (uMsg == ALF_WM_DPICHANGE && priv) {
+        priv->dpi = (int)lParam;
+        ALF_InvalidateLayout(GetParent(hwnd));
+        return TRUE;
+    }
+
     return DefWindowProc(hwnd, uMsg, wParam, lParam);
 }
 
@@ -295,7 +330,7 @@ ALF_InternalAddComboBox(HWND win, WORD id, int x, int y, DWORD style, const TCHA
     if (defaultText)
         SetWindowText(hwndCombo, defaultText);
 
-    ALF_AddWidget(win, x, y, hwndCombo, 0, 0, ALF_LAYOUT_SIZE_QUERY | ALF_LAYOUT_INHERITFONT);
+    ALF_AddWidget(win, x, y, hwndCombo, 0, 0, ALF_LAYOUT_SIZE_QUERY | ALF_LAYOUT_INHERITFONT | ALF_LAYOUT_SENDDPICHANGE);
 
     return hwndCombo;
 }