Fix Dialog Box example

dart-windows · Mar 23, 2024 · 3d6f3a8 · 3d6f3a8
1 parent 810926b
commit 3d6f3a8
Show file tree

Hide file tree

Showing 2 changed files with 44 additions and 39 deletions.
diff --git a/example/dialogbox.dart b/example/dialogbox.dart
@@ -14,9 +14,10 @@ import 'package:win32/win32.dart';
 const ID_TEXT = 200;
 const ID_EDITTEXT = 201;
 const ID_PROGRESS = 202;
+const PROGRESS_CLASS = 'msctls_progress32';
 
 final hInstance = GetModuleHandle(nullptr);
-String textEntered = '';
+String? textEntered;
 
 void main() {
   // Allocate 8KB, which is more than enough space for the dialog in memory.
@@ -31,7 +32,7 @@ void main() {
           DS_SETFONT |
           WINDOW_STYLE.WS_CAPTION,
       title: 'Sample dialog',
-      cdit: 4,
+      cdit: 5, // number of controls in the dialog
       cx: 300,
       cy: 200,
       fontName: 'MS Shell Dlg',
@@ -75,22 +76,23 @@ void main() {
 
   idx += (ptr + idx).cast<DLGITEMTEMPLATE>().setDialogItem(
       style: PBS_SMOOTH | WINDOW_STYLE.WS_BORDER | WINDOW_STYLE.WS_VISIBLE,
-      x: 6,
-      y: 49,
-      cx: 158,
+      x: 10,
+      y: 30,
+      cx: 150,
       cy: 12,
       id: ID_PROGRESS,
-      windowClass: 'msctls_progress32' // progress bar
+      windowClass: PROGRESS_CLASS // progress bar
       );
 
   idx += (ptr + idx).cast<DLGITEMTEMPLATE>().setDialogItem(
       style: WINDOW_STYLE.WS_CHILD |
           WINDOW_STYLE.WS_VISIBLE |
           WINDOW_STYLE.WS_TABSTOP |
-          WINDOW_STYLE.WS_BORDER,
-      x: 20,
+          WINDOW_STYLE.WS_BORDER |
+          ES_AUTOHSCROLL,
+      x: 10,
       y: 50,
-      cx: 100,
+      cx: 150,
       cy: 20,
       id: ID_EDITTEXT,
       windowSystemClass: 0x0081, // edit
@@ -107,7 +109,9 @@ void main() {
   if (nResult <= 0) {
     print('Error: $nResult');
   } else {
-    print('Entered: $textEntered');
+    if (textEntered != null) {
+      print('Entered: $textEntered');
+    }
   }
 
   lpDialogFunc.close();
@@ -119,26 +123,23 @@ void main() {
 int dialogReturnProc(int hwndDlg, int message, int wParam, int lParam) {
   switch (message) {
     case WM_INITDIALOG:
-      {
-        SendDlgItemMessage(hwndDlg, ID_PROGRESS, PBM_SETPOS, 35, 0);
-        break;
-      }
+      SendDlgItemMessage(hwndDlg, ID_PROGRESS, PBM_SETPOS, 35, 0);
     case WM_COMMAND:
-      {
-        switch (LOWORD(wParam)) {
-          case MESSAGEBOX_RESULT.IDOK:
-            print('OK');
-            final textPtr = wsalloc(256);
-            GetDlgItemText(hwndDlg, ID_EDITTEXT, textPtr, 256);
+      switch (LOWORD(wParam)) {
+        case MESSAGEBOX_RESULT.IDOK:
+          print('OK');
+          final textPtr = wsalloc(256);
+          final result = GetDlgItemText(hwndDlg, ID_EDITTEXT, textPtr, 256);
+          if (result != NULL) {
             textEntered = textPtr.toDartString();
-            free(textPtr);
-            EndDialog(hwndDlg, wParam);
-            return TRUE;
-          case MESSAGEBOX_RESULT.IDCANCEL:
-            print('Cancel');
-            EndDialog(hwndDlg, wParam);
-            return TRUE;
-        }
+          }
+          free(textPtr);
+          EndDialog(hwndDlg, wParam);
+          return TRUE;
+        case MESSAGEBOX_RESULT.IDCANCEL:
+          print('Cancel');
+          EndDialog(hwndDlg, wParam);
+          return TRUE;
       }
   }
 

diff --git a/lib/src/extensions/dialogs.dart b/lib/src/extensions/dialogs.dart
@@ -136,17 +136,21 @@ extension DialogItemTemplateHelper on Pointer<DLGITEMTEMPLATE> {
       ..id = id;
     idx += dlgItemTemplateSize;
 
-    /// Immediately following each DLGITEMTEMPLATE structure is a class array
-    /// that specifies the window class of the control. If the first element of
-    /// this array is any value other than 0xFFFF, the system treats the array
-    /// as a null-terminated Unicode string that specifies the name of a
-    /// registered window class. If the first element is 0xFFFF, the array has
-    /// one additional element that specifies the ordinal value of a predefined
-    /// system class.
-    ///
-    /// The ordinal can be one of the following atom values: 0x0080: Button
-    ///   0x0081: Edit 0x0082: Static 0x0083: List box 0x0084: Scroll bar
-    ///   0x0085: Combo box
+    // Immediately following each DLGITEMTEMPLATE structure is a class array
+    // that specifies the window class of the control. If the first element of
+    // this array is any value other than 0xFFFF, the system treats the array as
+    // a null-terminated Unicode string that specifies the name of a registered
+    // window class. If the first element is 0xFFFF, the array has one
+    // additional element that specifies the ordinal value of a predefined
+    // system class.
+    //
+    // The ordinal can be one of the following atom values:
+    // - 0x0080: Button
+    // - 0x0081: Edit
+    // - 0x0082: Static
+    // - 0x0083: List box
+    // - 0x0084: Scroll bar
+    // - 0x0085: Combo box
     if (windowClass.isNotEmpty) {
       idx += ((ptr + idx).cast<Utf16>().setString(windowClass) / 2).ceil();
     } else {