1  #include "flutter_window.h"
 2  
 3  #include <optional>
 4  
 5  #include "flutter/generated_plugin_registrant.h"
 6  
 7  FlutterWindow::FlutterWindow(const flutter::DartProject& project)
 8  	: project_(project) {}
 9  
10  FlutterWindow::~FlutterWindow() {}
11  
12  bool FlutterWindow::OnCreate() {
13  	if (!Win32Window::OnCreate()) {
14  		return false;
15  	}
16  
17  	RECT frame = GetClientArea();
18  
19  	// The size here must match the window dimensions to avoid unnecessary surface
20  	// creation / destruction in the startup path.
21  	flutter_controller_ = std::make_unique<flutter::FlutterViewController>(
22  			frame.right - frame.left, frame.bottom - frame.top, project_);
23  	// Ensure that basic setup of the controller was successful.
24  	if (!flutter_controller_->engine() || !flutter_controller_->view()) {
25  		return false;
26  	}
27  	RegisterPlugins(flutter_controller_->engine());
28  	SetChildContent(flutter_controller_->view()->GetNativeWindow());
29  
30  	flutter_controller_->engine()->SetNextFrameCallback([&]() {
31  		this->Show();
32  	});
33  
34  	// Flutter can complete the first frame before the "show window" callback is
35  	// registered. The following call ensures a frame is pending to ensure the
36  	// window is shown. It is a no-op if the first frame hasn't completed yet.
37  	flutter_controller_->ForceRedraw();
38  
39  	return true;
40  }
41  
42  void FlutterWindow::OnDestroy() {
43  	if (flutter_controller_) {
44  		flutter_controller_ = nullptr;
45  	}
46  
47  	Win32Window::OnDestroy();
48  }
49  
50  LRESULT
51  FlutterWindow::MessageHandler(HWND hwnd, UINT const message,
52  															WPARAM const wparam,
53  															LPARAM const lparam) noexcept {
54  	// Give Flutter, including plugins, an opportunity to handle window messages.
55  	if (flutter_controller_) {
56  		std::optional<LRESULT> result =
57  				flutter_controller_->HandleTopLevelWindowProc(hwnd, message, wparam,
58  																											lparam);
59  		if (result) {
60  			return *result;
61  		}
62  	}
63  
64  	switch (message) {
65  		case WM_FONTCHANGE:
66  			flutter_controller_->engine()->ReloadSystemFonts();
67  			break;
68  	}
69  
70  	return Win32Window::MessageHandler(hwnd, message, wparam, lparam);
71  }