window_manager.cc

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// Copyright 2013 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
 
#include "flutter/shell/platform/windows/window_manager.h"
 
#include <dwmapi.h>
#include <optional>
#include <vector>
 
#include "embedder.h"
#include "flutter/shell/platform/common/windowing.h"
#include "flutter/shell/platform/windows/flutter_windows_engine.h"
#include "flutter/shell/platform/windows/flutter_windows_view_controller.h"
#include "flutter/shell/platform/windows/host_window.h"
#include "fml/logging.h"
#include "shell/platform/windows/client_wrapper/include/flutter/flutter_view.h"
#include "shell/platform/windows/flutter_windows_view.h"
#include "shell/platform/windows/host_window.h"
#include "shell/platform/windows/host_window_tooltip.h"
 
namespace flutter {
 
WindowManager::WindowManager(FlutterWindowsEngine* engine) : engine_(engine) {}
 
void WindowManager::Initialize(const WindowingInitRequest* request) {
  on_message_ = request->on_message;
  isolate_ = Isolate::Current();
}
 
FlutterViewId WindowManager::CreateRegularWindow(
    const RegularWindowCreationRequest* request) {
  auto window = HostWindow::CreateRegularWindow(
      this, engine_, request->preferred_size, request->preferred_constraints,
      request->title);
  if (!window || !window->GetWindowHandle()) {
    FML_LOG(ERROR) << "Failed to create host window";
    return -1;
  }
  FlutterViewId const view_id = window->view_controller_->view()->view_id();
  active_windows_[window->GetWindowHandle()] = std::move(window);
  return view_id;
}
 
FlutterViewId WindowManager::CreateDialogWindow(
    const DialogWindowCreationRequest* request) {
  auto window = HostWindow::CreateDialogWindow(
      this, engine_, request->preferred_size, request->preferred_constraints,
      request->title, request->parent_or_null);
  if (!window || !window->GetWindowHandle()) {
    FML_LOG(ERROR) << "Failed to create host window";
    return -1;
  }
  FlutterViewId const view_id = window->view_controller_->view()->view_id();
  active_windows_[window->GetWindowHandle()] = std::move(window);
  return view_id;
}
 
FlutterViewId WindowManager::CreateTooltipWindow(
    const TooltipWindowCreationRequest* request) {
  auto window = HostWindow::CreateTooltipWindow(
      this, engine_, request->preferred_constraints,
      request->get_position_callback, request->parent);
  if (!window || !window->GetWindowHandle()) {
    FML_LOG(ERROR) << "Failed to create host window";
    return -1;
  }
  FlutterViewId const view_id = window->view_controller_->view()->view_id();
  active_windows_[window->GetWindowHandle()] = std::move(window);
  return view_id;
}
 
void WindowManager::OnEngineShutdown() {
  // Don't send any more messages to isolate.
  on_message_ = nullptr;
  std::vector<HWND> active_handles;
  active_handles.reserve(active_windows_.size());
  for (auto& [hwnd, window] : active_windows_) {
    active_handles.push_back(hwnd);
  }
  for (auto hwnd : active_handles) {
    // This will destroy the window, which will in turn remove the
    // HostWindow from map when handling WM_NCDESTROY inside
    // HandleMessage.
    InternalFlutterWindows_WindowManager_OnDestroyWindow(hwnd);
  }
}
 
std::optional<LRESULT> WindowManager::HandleMessage(HWND hwnd,
                                                    UINT message,
                                                    WPARAM wparam,
                                                    LPARAM lparam) {
  if (message == WM_NCDESTROY) {
    active_windows_.erase(hwnd);
    return std::nullopt;
  }
 
  HostWindow* host_window = HostWindow::GetThisFromHandle(hwnd);
  FlutterWindowsView* view =
      host_window ? host_window->view_controller_->view() : nullptr;
 
  if (!view) {
    FML_LOG(WARNING) << "Received message for unknown view";
    return std::nullopt;
  }
 
  WindowsMessage message_struct = {.view_id = view->view_id(),
                                   .hwnd = hwnd,
                                   .message = message,
                                   .wParam = wparam,
                                   .lParam = lparam,
                                   .result = 0,
                                   .handled = false};
 
  // Not initialized yet.
  if (!isolate_) {
    return std::nullopt;
  }
 
  IsolateScope scope(*isolate_);
  on_message_(&message_struct);
  if (message_struct.handled) {
    return message_struct.result;
  } else {
    return std::nullopt;
  }
}
 
}  // namespace flutter
 
void InternalFlutterWindows_WindowManager_Initialize(
    int64_t engine_id,
    const flutter::WindowingInitRequest* request) {
  flutter::FlutterWindowsEngine* engine =
      flutter::FlutterWindowsEngine::GetEngineForId(engine_id);
  engine->window_manager()->Initialize(request);
}
 
FlutterViewId InternalFlutterWindows_WindowManager_CreateRegularWindow(
    int64_t engine_id,
    const flutter::RegularWindowCreationRequest* request) {
  flutter::FlutterWindowsEngine* engine =
      flutter::FlutterWindowsEngine::GetEngineForId(engine_id);
  return engine->window_manager()->CreateRegularWindow(request);
}
 
FLUTTER_EXPORT
FlutterViewId InternalFlutterWindows_WindowManager_CreateDialogWindow(
    int64_t engine_id,
    const flutter::DialogWindowCreationRequest* request) {
  flutter::FlutterWindowsEngine* engine =
      flutter::FlutterWindowsEngine::GetEngineForId(engine_id);
  return engine->window_manager()->CreateDialogWindow(request);
}
 
FLUTTER_EXPORT
FlutterViewId InternalFlutterWindows_WindowManager_CreateTooltipWindow(
    int64_t engine_id,
    const flutter::TooltipWindowCreationRequest* request) {
  flutter::FlutterWindowsEngine* engine =
      flutter::FlutterWindowsEngine::GetEngineForId(engine_id);
  return engine->window_manager()->CreateTooltipWindow(request);
}
 
HWND InternalFlutterWindows_WindowManager_GetTopLevelWindowHandle(
    int64_t engine_id,
    FlutterViewId view_id) {
  flutter::FlutterWindowsEngine* engine =
      flutter::FlutterWindowsEngine::GetEngineForId(engine_id);
  flutter::FlutterWindowsView* view = engine->view(view_id);
  if (view == nullptr) {
    return nullptr;
  } else {
    return GetAncestor(view->GetWindowHandle(), GA_ROOT);
  }
}
 
flutter::ActualWindowSize
InternalFlutterWindows_WindowManager_GetWindowContentSize(HWND hwnd) {
  return flutter::HostWindow::GetWindowContentSize(hwnd);
}
 
void InternalFlutterWindows_WindowManager_SetWindowSize(
    HWND hwnd,
    const flutter::WindowSizeRequest* size) {
  flutter::HostWindow* window = flutter::HostWindow::GetThisFromHandle(hwnd);
  if (window) {
    window->SetContentSize(*size);
  }
}
 
void InternalFlutterWindows_WindowManager_OnDestroyWindow(HWND hwnd) {
  flutter::HostWindow* window = flutter::HostWindow::GetThisFromHandle(hwnd);
  HWND flutter_view_handle = nullptr;
  if (window) {
    // First reparent the FlutterView to null parent. Otherwise destroying
    // the window HWND will immediately destroy the FlutterView HWND as well,
    // which will cause crash when raster thread tries to reallocate surface.
    // The FlutterView may only be destroyed safely when
    // FlutterWindowsEngine::RemoveView finishes.
    flutter_view_handle = window->GetFlutterViewWindowHandle();
    ShowWindow(flutter_view_handle, SW_HIDE);
    SetParent(flutter_view_handle, nullptr);
  }
  DestroyWindow(hwnd);
  if (flutter_view_handle) {
    // Now the flutter view HWND can be destroyed safely.
    DestroyWindow(flutter_view_handle);
  }
}
 
void InternalFlutterWindows_WindowManager_SetWindowConstraints(
    HWND hwnd,
    const flutter::WindowConstraints* constraints) {
  flutter::HostWindow* window = flutter::HostWindow::GetThisFromHandle(hwnd);
  if (window) {
    window->SetConstraints(*constraints);
  }
}
 
void InternalFlutterWindows_WindowManager_SetFullscreen(
    HWND hwnd,
    const flutter::FullscreenRequest* request) {
  flutter::HostWindow* window = flutter::HostWindow::GetThisFromHandle(hwnd);
  const std::optional<FlutterEngineDisplayId> display_id =
      request->has_display_id
          ? std::optional<FlutterEngineDisplayId>(request->display_id)
          : std::nullopt;
  if (window) {
    window->SetFullscreen(request->fullscreen, display_id);
  }
}
 
bool InternalFlutterWindows_WindowManager_GetFullscreen(HWND hwnd) {
  flutter::HostWindow* window = flutter::HostWindow::GetThisFromHandle(hwnd);
  if (window) {
    return window->GetFullscreen();
  }
 
  return false;
}
 
FLUTTER_EXPORT
void InternalFlutterWindows_WindowManager_UpdateTooltipPosition(HWND hwnd) {
  flutter::HostWindow* window = flutter::HostWindow::GetThisFromHandle(hwnd);
  flutter::HostWindowTooltip* tooltip_window =
      reinterpret_cast<flutter::HostWindowTooltip*>(window);
  tooltip_window->UpdatePosition();
}