[Win] Implement dialog.showSaveDialog.

atom.gyp

@@ -322,6 +322,7 @@
             'libraries': [
               '-limm32.lib',
               '-loleacc.lib',
+              '-lComdlg32.lib',
               '<(atom_source_root)/<(libchromiumcontent_library_dir)/chromiumviews.lib',
             ],
           },

browser/file_dialog_win.cc

@@ -4,8 +4,78 @@
 
 #include "browser/file_dialog.h"
 
+#include <windows.h>
+#include <commdlg.h>
+#include <shlobj.h>
+
+#include "base/file_util.h"
+#include "base/string_util.h"
+#include "base/win/windows_version.h"
+#include "browser/native_window.h"
+
 namespace file_dialog {
 
+namespace {
+
+// Distinguish directories from regular files.
+bool IsDirectory(const base::FilePath& path) {
+  base::PlatformFileInfo file_info;
+  return file_util::GetFileInfo(path, &file_info) ?
+      file_info.is_directory : path.EndsWithSeparator();
+}
+
+// Enforce visible dialog box.
+UINT_PTR CALLBACK SaveAsDialogHook(HWND dialog, UINT message,
+                                   WPARAM wparam, LPARAM lparam) {
+  static const UINT kPrivateMessage = 0x2F3F;
+  switch (message) {
+    case WM_INITDIALOG: {
+      // Do nothing here. Just post a message to defer actual processing.
+      PostMessage(dialog, kPrivateMessage, 0, 0);
+      return TRUE;
+    }
+    case kPrivateMessage: {
+      // The dialog box is the parent of the current handle.
+      HWND real_dialog = GetParent(dialog);
+
+      // Retrieve the final size.
+      RECT dialog_rect;
+      GetWindowRect(real_dialog, &dialog_rect);
+
+      // Verify that the upper left corner is visible.
+      POINT point = { dialog_rect.left, dialog_rect.top };
+      HMONITOR monitor1 = MonitorFromPoint(point, MONITOR_DEFAULTTONULL);
+      point.x = dialog_rect.right;
+      point.y = dialog_rect.bottom;
+
+      // Verify that the lower right corner is visible.
+      HMONITOR monitor2 = MonitorFromPoint(point, MONITOR_DEFAULTTONULL);
+      if (monitor1 && monitor2)
+        return 0;
+
+      // Some part of the dialog box is not visible, fix it by moving is to the
+      // client rect position of the browser window.
+      HWND parent_window = GetParent(real_dialog);
+      if (!parent_window)
+        return 0;
+      WINDOWINFO parent_info;
+      parent_info.cbSize = sizeof(WINDOWINFO);
+      GetWindowInfo(parent_window, &parent_info);
+      SetWindowPos(real_dialog, NULL,
+                   parent_info.rcClient.left,
+                   parent_info.rcClient.top,
+                   0, 0,  // Size.
+                   SWP_NOACTIVATE | SWP_NOOWNERZORDER | SWP_NOSIZE |
+                   SWP_NOZORDER);
+
+      return 0;
+    }
+  }
+  return 0;
+}
+
+}  // namespace
+
 bool ShowOpenDialog(const std::string& title,
                     const base::FilePath& default_path,
                     int properties,
@@ -17,7 +87,80 @@ bool ShowSaveDialog(atom::NativeWindow* window,
                     const std::string& title,
                     const base::FilePath& default_path,
                     base::FilePath* path) {
-  return false;
+  std::wstring file_part = default_path.BaseName().value();
+  // If the default_path is a root directory, file_part will be '\', and the
+  // call to GetSaveFileName below will fail.
+  if (file_part.size() == 1 && file_part[0] == L'\\')
+    file_part.clear();
+
+  // The size of the in/out buffer in number of characters we pass to win32
+  // GetSaveFileName.  From MSDN "The buffer must be large enough to store the
+  // path and file name string or strings, including the terminating NULL
+  // character.  ... The buffer should be at least 256 characters long.".
+  // _IsValidPathComDlg does a copy expecting at most MAX_PATH, otherwise will
+  // result in an error of FNERR_INVALIDFILENAME.  So we should only pass the
+  // API a buffer of at most MAX_PATH.
+  wchar_t file_name[MAX_PATH];
+  base::wcslcpy(file_name, file_part.c_str(), arraysize(file_name));
+
+  OPENFILENAME save_as;
+  // We must do this otherwise the ofn's FlagsEx may be initialized to random
+  // junk in release builds which can cause the Places Bar not to show up!
+  ZeroMemory(&save_as, sizeof(save_as));
+  save_as.lStructSize = sizeof(OPENFILENAME);
+  save_as.hwndOwner = window->GetNativeWindow();
+  save_as.hInstance = NULL;
+
+  // TODO(zcbenz): Should support filters.
+  save_as.lpstrFilter = NULL;
+  save_as.nFilterIndex = 0;
+
+  save_as.lpstrCustomFilter = NULL;
+  save_as.nMaxCustFilter = 0;
+  save_as.lpstrFile = file_name;
+  save_as.nMaxFile = arraysize(file_name);
+  save_as.lpstrFileTitle = NULL;
+  save_as.nMaxFileTitle = 0;
+
+  // Set up the initial directory for the dialog.
+  std::wstring directory;
+  if (IsDirectory(default_path)) {
+    directory = default_path.value();
+    file_part.clear();
+  } else {
+    directory = default_path.DirName().value();
+  }
+
+  save_as.lpstrInitialDir = directory.c_str();
+  save_as.lpstrTitle = NULL;
+  save_as.Flags = OFN_OVERWRITEPROMPT | OFN_EXPLORER | OFN_ENABLESIZING |
+                  OFN_NOCHANGEDIR | OFN_PATHMUSTEXIST;
+  save_as.lpstrDefExt = NULL;  // default extension, ignored for now.
+  save_as.lCustData = NULL;
+
+  if (base::win::GetVersion() < base::win::VERSION_VISTA) {
+    // The save as on Windows XP remembers its last position,
+    // and if the screen resolution changed, it will be off screen.
+    save_as.Flags |= OFN_ENABLEHOOK;
+    save_as.lpfnHook = &SaveAsDialogHook;
+  }
+
+  // Must be NULL or 0.
+  save_as.pvReserved = NULL;
+  save_as.dwReserved = 0;
+
+  if (!GetSaveFileName(&save_as)) {
+    // Zero means the dialog was closed, otherwise we had an error.
+    DWORD error_code = CommDlgExtendedError();
+    if (error_code != 0) {
+      NOTREACHED() << "GetSaveFileName failed with code: " << error_code;
+    }
+    return false;
+  }
+
+  // Return the user's choice.
+  *path = base::FilePath(save_as.lpstrFile);
+  return true;
 }
 
 }  // namespace file_dialog