first try at combobox implementation

1 files changed, 270 insertions, 0 deletions

diff --git a/alf/alfcombobox.cpp b/alf/alfcombobox.cpp
new file mode 100644
index 0000000..43c547a
--- /dev/null
+++ b/alf/alfcombobox.cpp
@@ -0,0 +1,270 @@
+#include "alfpriv.h"
+
+typedef struct {
+    ALFAPP app;
+    DWORD  comboStyle;
+} ALFComboCreateParams;
+
+static int
+ALF__ComboItemHeight(HWND hwnd)
+{
+    int height = 0;
+    HDC hDc = GetDC(hwnd);
+    HFONT font = (HFONT)SendMessage(hwnd, WM_GETFONT, 0, 0);
+    if (font) {
+        HFONT oldfont = SelectFont(hDc, font);
+
+        TEXTMETRIC tm;
+        ZeroMemory(&tm, sizeof(tm));
+
+        if (GetTextMetrics(hDc, &tm)) {
+            height = tm.tmHeight;
+        }
+
+        SelectFont(hDc, oldfont);
+    }
+
+    ReleaseDC(hwnd, hDc);
+    return height;
+}
+
+static LRESULT CALLBACK
+ALF__ComboWindowProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
+{
+    if (uMsg == WM_NCCREATE) {
+        ALFComboCreateParams *params = (ALFComboCreateParams*)((CREATESTRUCT*)lParam)->lpCreateParams;
+
+        SetWindowLongPtr(hwnd, 0, (LONG_PTR)params->app);
+    }
+
+    ALFAPP app = (ALFAPP)GetWindowLongPtr(hwnd, 0);
+    HWND   hwndChild = (HWND)GetWindowLongPtr(hwnd, sizeof(void*));
+
+    if (uMsg == WM_CREATE) {
+        ALFComboCreateParams *params = (ALFComboCreateParams*)((CREATESTRUCT*)lParam)->lpCreateParams;
+        HWND hwndCombo = CreateWindowEx(0,
+                                        TEXT("COMBOBOX"),
+                                        TEXT(""),
+                                        WS_CHILD | WS_VISIBLE | WS_TABSTOP | CBS_OWNERDRAWFIXED | CBS_HASSTRINGS | params->comboStyle,
+                                        0, 0, 0, 200 /* FIXME needed for commctl32 v5, what is the best value here? */,
+                                        hwnd,
+                                        (HMENU) GetWindowLongPtrW(hwnd, GWLP_ID),
+                                        ((CREATESTRUCT*)lParam)->hInstance,
+                                        NULL);
+
+        SetWindowLongPtr(hwnd, sizeof(void*), (LONG_PTR)hwndCombo);
+    }
+    if (uMsg == WM_ENABLE && hwndChild) {
+        EnableWindow(hwndChild, (BOOL)wParam);
+        return 0;
+    }
+    if (uMsg == WM_SETTEXT && hwndChild) {
+        return SendMessage(hwndChild, WM_SETTEXT, wParam, lParam);
+    }
+    if (uMsg == WM_GETTEXTLENGTH && hwndChild) {
+        return SendMessage(hwndChild, WM_GETTEXTLENGTH, wParam, lParam);
+    }
+    if (uMsg == WM_GETTEXT && hwndChild) {
+        return SendMessage(hwndChild, WM_GETTEXT, wParam, lParam);
+    }
+    if (uMsg == WM_SETFONT && hwndChild) {
+        SendMessage(hwndChild, WM_SETFONT, wParam, lParam);
+
+        int h = ALF__ComboItemHeight(hwnd);
+        if (h)
+            SendMessage(hwndChild, CB_SETITEMHEIGHT, (WPARAM)0, h);
+
+        return 0;
+    }
+    if (uMsg == WM_GETFONT && hwndChild) {
+        return SendMessage(hwndChild, WM_GETFONT, wParam, lParam);
+    }
+    if (uMsg == CB_ADDSTRING && hwndChild) {
+        return SendMessage(hwndChild, CB_ADDSTRING, wParam, lParam);
+    }
+
+    if (uMsg == ALF_WM_QUERYSIZE) {
+        HDC hDc = GetDC(hwnd);
+        HFONT font = (HFONT)SendMessage(hwnd, WM_GETFONT, 0, 0);
+
+        if (font) {
+            HFONT oldfont = SelectFont(hDc, font);
+
+            TEXTMETRIC tm;
+            ZeroMemory(&tm, sizeof(tm));
+
+            if (GetTextMetrics(hDc, &tm)) {
+                SIZE *ps = (SIZE*)lParam;
+                if (!ps->cx) {
+                    ps->cx = ALF_CentipointsToPixels(GetParent(hwnd), 12000);
+                }
+
+                if (!ps->cy) {
+                    ps->cy = tm.tmHeight + 2*app->compatFn->GetSystemMetricsForDpi(
+                            SM_CYEDGE, ALF_CentipointsToPixels(GetParent(hwnd), 7200))
+                        + 4 /* padding internal to the edit control */
+                        + 2 /* external padding to line up with themed button */;
+                }
+            }
+
+            SelectFont(hDc, oldfont);
+        }
+
+        ReleaseDC(hwnd, hDc);
+        return 0;
+    }
+
+    if (uMsg == WM_MEASUREITEM) {
+        PMEASUREITEMSTRUCT lpmis = (LPMEASUREITEMSTRUCT) lParam;
+
+        int h = ALF__ComboItemHeight(hwnd);
+        if (h)
+            lpmis->itemHeight = h;
+
+        return TRUE;
+    }
+
+    if (uMsg == WM_DRAWITEM) {
+        LPDRAWITEMSTRUCT lpdis = (LPDRAWITEMSTRUCT) lParam;
+
+        if (lpdis->itemID != (UINT)-1) { // Empty item
+            DWORD clrForeground = SetTextColor(lpdis->hDC,
+                GetSysColor(lpdis->itemState & (ODS_SELECTED | ODS_FOCUS) ?
+                COLOR_HIGHLIGHTTEXT : COLOR_WINDOWTEXT));
+
+            DWORD clrBackground = SetBkColor(lpdis->hDC,
+                GetSysColor(lpdis->itemState & (ODS_SELECTED | ODS_FOCUS) ?
+                COLOR_HIGHLIGHT : COLOR_WINDOW));
+
+            LONG y = lpdis->rcItem.top;
+            LONG x = lpdis->rcItem.left;
+
+            // add left padding like an edit control
+            TEXTMETRIC tm;
+            ZeroMemory(&tm, sizeof(tm));
+            if (GetTextMetrics(lpdis->hDC, &tm)) {
+                if (tm.tmPitchAndFamily & (TMPF_VECTOR | TMPF_TRUETYPE))
+                    x += ALF_GetAveCharWidth(lpdis->hDC) / 2;
+            }
+
+            // Get and display the text for the list item.
+            int len = (int)SendMessage(lpdis->hwndItem, CB_GETLBTEXTLEN, (WPARAM)lpdis->itemID, 0);
+            if (len != CB_ERR) {
+                TCHAR *buf = (TCHAR*)LocalAlloc(LPTR, (len+1) * sizeof(TCHAR));
+
+                SendMessage(lpdis->hwndItem, CB_GETLBTEXT,
+                    lpdis->itemID, (LPARAM)buf);
+
+                ExtTextOut(lpdis->hDC, x, y,
+                    ETO_CLIPPED | ETO_OPAQUE, &lpdis->rcItem,
+                    buf, lstrlen(buf), NULL);
+
+                LocalFree(buf);
+            }
+
+            // Restore the previous colors.
+            SetTextColor(lpdis->hDC, clrForeground);
+            SetBkColor(lpdis->hDC, clrBackground);
+        }
+
+        // If the item has the focus, draw the focus rectangle.
+        if ((lpdis->itemState & ODS_FOCUS) && !(lpdis->itemState & ODS_NOFOCUSRECT))
+            DrawFocusRect(lpdis->hDC, &lpdis->rcItem);
+
+        return TRUE;
+    }
+
+    if (uMsg == WM_WINDOWPOSCHANGED && hwndChild) {
+        WINDOWPOS *pos = (WINDOWPOS *)lParam;
+        if (!(pos->flags & SWP_NOSIZE)) {
+            RECT r;
+            GetWindowRect(hwndChild, &r);
+            SetWindowPos(hwndChild, NULL, 0, 1, pos->cx, r.bottom - r.top, SWP_NOZORDER|SWP_NOACTIVATE);
+
+            SendMessage(hwndChild, CB_SETITEMHEIGHT, (WPARAM)-1, pos->cy - 8);
+
+            int h = ALF__ComboItemHeight(hwnd);
+            if (h)
+                SendMessage(hwndChild, CB_SETITEMHEIGHT, (WPARAM)0, h);
+        }
+    }
+
+    return DefWindowProc(hwnd, uMsg, wParam, lParam);
+}
+
+
+void
+ALF_RegisterComboClass(ALFAPP app)
+{
+    WNDCLASS cls;
+    ZeroMemory(&cls, sizeof(cls));
+
+    TCHAR  classNameBuf[256];
+    ALF_BuildRandomClassName(TEXT("ALFComboBox."), classNameBuf);
+
+    cls.hInstance = app->hInstance;
+    cls.hCursor = LoadCursor(NULL, (LPTSTR)IDC_ARROW);
+    cls.hbrBackground = (HBRUSH)(COLOR_BTNFACE+1);
+    cls.lpszClassName = classNameBuf;
+    cls.cbWndExtra = sizeof(void*)*2;
+    cls.lpfnWndProc = ALF__ComboWindowProc;
+
+    ATOM classatom = RegisterClass(&cls);
+    if (!classatom)
+        MessageBox(NULL, TEXT("FATAL: Could not register Combo class"), NULL, MB_OK);
+
+    app->comboClass = MAKEINTATOM(classatom);
+}
+
+static HWND
+ALF_InternalAddComboBox(HWND win, WORD id, UINT x, UINT y, DWORD style, const TCHAR *defaultText)
+{
+    ALFComboCreateParams cp;
+    cp.app = ALF_ApplicationFromWindow(win);
+    cp.comboStyle = style;
+
+    HWND hwndCombo = CreateWindowEx(WS_EX_CONTROLPARENT,
+                                    cp.app->comboClass,
+                                    TEXT(""),
+                                    WS_CHILD | WS_VISIBLE | WS_CLIPCHILDREN,
+                                    0, 0, 0, 0,
+                                    win,
+                                    (HMENU)(int)id,
+                                    (HINSTANCE)GetWindowLongPtr(win, GWLP_HINSTANCE),
+                                    &cp);
+
+    if (defaultText)
+        SetWindowText(hwndCombo, defaultText);
+
+    ALFAddWidgetParams p;
+    ZeroMemory(&p, sizeof(p));
+    p.hwnd = hwndCombo;
+    p.x = x;
+    p.y = y;
+    p.width = 0;
+    p.height = 0;
+    p.flags = ALF_QUERYSIZE | ALF_MESSAGEFONT;
+
+    ALF_AddWidgetEx(win, &p);
+
+    return hwndCombo;
+}
+
+HWND
+ALF_AddEditableComboBox(HWND win, WORD id, UINT x, UINT y, const TCHAR *defaultText)
+{
+    return ALF_InternalAddComboBox(win, id, x, y, CBS_DROPDOWN, defaultText);
+}
+
+HWND
+ALF_AddSelectionOnlyComboBox(HWND win, WORD id, UINT x, UINT y)
+{
+    return ALF_InternalAddComboBox(win, id, x, y, CBS_DROPDOWNLIST, NULL);
+}
+
+int /* index */
+ALF_ComboBoxAddString(HWND combo, const TCHAR *text)
+{
+    return (int)SendMessage(combo, CB_ADDSTRING, 0, (LPARAM)text);
+}
+