Download updates automatically, ask to install from a modeless dialog

src/engine/UpdateInstallDialog.cpp

+#include <sstream>
+#include <string>
+#include <Windows.h>
+
+#include "../shared/Dictionary.h"
+#include "../shared/Utils.h"
+#include "UpdateInstallDialog.h"
+
+namespace
+{
+  LRESULT CALLBACK ProcessWindowMessage(HWND window, UINT message,
+                                        WPARAM wParam, LPARAM lParam)
+  {
+    switch (message)
+    {
+    case WM_CLOSE:
+      PostQuitMessage(0);
+      return 0;
+    case WM_COMMAND:
+      switch (LOWORD(wParam))
+      {
+      case IDYES:
+        PostQuitMessage(1);
+        return 0;
+      case IDNO:
+        PostQuitMessage(0);
+        return 0;
+      }
+      break;
+    }
+    return DefWindowProc(window, message, wParam, lParam);
+  }
+}
+
+UpdateInstallDialog::UpdateInstallDialog()
+{
+  const std::wstring windowClassName = L"UPDATE_INSTALL_DIALOG";
+  WNDCLASSEX windowClass = {};

[Wladimir Palant, 2013/08/01 09:58:24]

We should use WNDCLASSEXW explicitly.

+  windowClass.cbSize = sizeof(WNDCLASSEX);

[Wladimir Palant, 2013/08/01 09:58:24]

sizeof(windowClass) to avoid repeating the type name?

[Felix Dahlke, 2013/08/02 10:48:01]

Done.

+  windowClass.lpfnWndProc = ProcessWindowMessage;
+  windowClass.hbrBackground = reinterpret_cast<HBRUSH>(COLOR_MENU + 1);
+  windowClass.lpszClassName = windowClassName.c_str();

[Oleksandr, 2013/08/01 07:05:12]

Maybe use hIcon here with ABP logo? A default window icon popping up out of the
blue isn't exactly a good user experience, I think.

+  if (!RegisterClassEx(&windowClass))
+  {
+    std::stringstream stream;
+    stream << "Failed to register window class "
+           << ToUtf8String(windowClassName) << ": " << GetLastError();
+    throw std::runtime_error(stream.str());
+  }
+
+  Dictionary* dictionary = Dictionary::GetInstance();
+  std::wstring title = dictionary->Lookup("updater", "install-question-title");

[Oleksandr, 2013/07/31 22:16:59]

This is fine only for when download is ready. How about also having an
overridden constructor that would be something like:
UpdateInstallDialog::UpdateInstallDialog(std::wstring title, std::wstring
message)? 

[Felix Dahlke, 2013/08/01 07:21:17]

Like I said earlier, I think it's better to focus on what we want to do for now,
not on what we could do. We can always change this later.

+
+  RECT workArea;
+  SystemParametersInfo(SPI_GETWORKAREA, 0, &workArea, 0);
+
+  const int width = 300;
+  const int height = 150;

[Wladimir Palant, 2013/08/01 09:58:24]

Where do these numbers come from? What will happen on high-DPI screens or with
lengthy translations? I suggest you measure the text size to determine window
size.

[Felix Dahlke, 2013/08/02 10:48:01]

Done.

+  const int margin = 10;
+
+  window = CreateWindowExW(WS_EX_TOOLWINDOW | WS_EX_TOPMOST,
+                           windowClassName.c_str(), title.c_str(), WS_SYSMENU,
+                           workArea.right - width - margin,
+                           workArea.bottom - height - margin,
+                           width, height, 0, 0, 0, 0);

[Oleksandr, 2013/08/01 07:05:12]

Should we do something like:

SetForegroundWindow(window);

It will flash the window in the taskbar, if the user is working in another
window. So that the user will notice it.

+  CreateText();
+  CreateButtons();

[Oleksandr, 2013/07/31 22:16:59]

No CreateButtons() in the overridden constructor I suggest. Or maybe something
like CreateOKButton().

[Felix Dahlke, 2013/08/01 07:21:17]

As I said above, let's make this more generic when we need that.

+}
+
+UpdateInstallDialog::~UpdateInstallDialog()
+{
+  DestroyWindow(window);
+}
+
+bool UpdateInstallDialog::Show()
+{
+  ShowWindow(window, SW_SHOW);
+  MSG message;
+  while(GetMessage(&message, 0, 0, 0) > 0)
+  {
+    TranslateMessage(&message);
+    DispatchMessage(&message);
+  }
+  ShowWindow(window, SW_HIDE);
+  return message.wParam;

[Wladimir Palant, 2013/08/01 09:58:24]

Doesn't this cause a warning? I would rather cast to bool explicitly here.

[Felix Dahlke, 2013/08/02 10:48:01]

Done. Opted for message.wParam == 0 in case of yes. This is logically an exit
code, so 0 makes more sense for the positive outcome.

+}
+
+void UpdateInstallDialog::CreateText()
+{
+  Dictionary* dictionary = Dictionary::GetInstance();
+  std::wstring text = dictionary->Lookup("updater", "install-question-text");
+
+  RECT clientRect;
+  GetClientRect(window, &clientRect);
+
+  const int margin = 10;
+  const int width = clientRect.right - margin * 2;
+  const int height = 60;
+
+  CreateWindowW(L"STATIC", text.c_str(), WS_CHILD | WS_VISIBLE| SS_LEFT,
+                margin, margin, width, height, window, 0, 0, 0);
+}
+
+void UpdateInstallDialog::CreateButtons()
+{
+  Dictionary* dictionary = Dictionary::GetInstance();
+  const std::wstring yesLabel = dictionary->Lookup("general", "button-yes");
+  const std::wstring noLabel = dictionary->Lookup("general", "button-no");
+
+  const DWORD buttonFlags = WS_CHILD | WS_VISIBLE;
+
+  RECT clientRect;
+  GetClientRect(window, &clientRect);
+
+  const int buttonWidth = 100;
+  const int buttonHeight = 30;

[Felix Dahlke, 2013/08/02 10:48:01]

Done.

+  const int margin = 10;
+  const int combinedWidth = buttonWidth * 2 + margin;
+  const int yesButtonX = clientRect.right - combinedWidth - margin;
+  const int noButtonX = yesButtonX + buttonWidth + margin;
+  const int buttonY = clientRect.bottom - buttonHeight - margin;
+
+  CreateWindowW(L"BUTTON", yesLabel.c_str(), buttonFlags,
+                yesButtonX, buttonY, buttonWidth, buttonHeight,
+                window, reinterpret_cast<HMENU>(IDYES), 0, 0);
+  CreateWindowW(L"BUTTON", noLabel.c_str(), buttonFlags,
+                noButtonX, buttonY, buttonWidth, buttonHeight,
+                window, reinterpret_cast<HMENU>(IDNO), 0, 0);
+}