windows/runner/win32_window.hH
#ifndef RUNNER_WIN32_WINDOW_H_
#define RUNNER_WIN32_WINDOW_H_
#include <windows.h>
#include <functional>
#include <memory>
#include <string>
// A class abstraction for a high DPI-aware Win32 Window. Intended to be
// inherited from by classes that wish to specialize with custom
// rendering and input handling
class Win32Window {
public:
struct Point {
unsigned int x;
unsigned int y;
Point(unsigned int x, unsigned int y) : x(x), y(y) {}
};
struct Size {
unsigned int width;
unsigned int height;
Size(unsigned int width, unsigned int height)
: width(width), height(height) {}
};
Win32Window();
virtual ~Win32Window();
// Creates a win32 window with |title| that is positioned and sized using
// |origin| and |size|. New windows are created on the default monitor. Window
// sizes are specified to the OS in physical pixels, hence to ensure a
// consistent size this function will scale the inputted width and height as
// as appropriate for the default monitor. The window is invisible until
// |Show| is called. Returns true if the window was created successfully.
bool Create(const std::wstring& title, const Point& origin, const Size& size);
// Show the current window. Returns true if the window was successfully shown.
bool Show();
// Release OS resources associated with window.
void Destroy();
// Inserts |content| into the window tree.
void SetChildContent(HWND content);
// Returns the backing Window handle to enable clients to set icon and other
// window properties. Returns nullptr if the window has been destroyed.
HWND GetHandle();
// If true, closing this window will quit the application.
void SetQuitOnClose(bool quit_on_close);
// Return a RECT representing the bounds of the current client area.
RECT GetClientArea();
protected:
// Processes and route salient window messages for mouse handling,
// size change and DPI. Delegates handling of these to member overloads that
// inheriting classes can handle.
virtual LRESULT MessageHandler(HWND window,
UINT const message,
WPARAM const wparam,
LPARAM const lparam) noexcept;
// Called when CreateAndShow is called, allowing subclass window-related
// setup. Subclasses should return false if setup fails.
virtual bool OnCreate();
// Called when Destroy is called.
virtual void OnDestroy();
private:
friend class WindowClassRegistrar;
// OS callback called by message pump. Handles the WM_NCCREATE message which
// is passed when the non-client area is being created and enables automatic
// non-client DPI scaling so that the non-client area automatically
// responds to changes in DPI. All other messages are handled by
// MessageHandler.
static LRESULT CALLBACK WndProc(HWND const window,
UINT const message,
WPARAM const wparam,
LPARAM const lparam) noexcept;
// Retrieves a class instance pointer for |window|
static Win32Window* GetThisFromHandle(HWND const window) noexcept;
// Update the window frame's theme to match the system theme.
static void UpdateTheme(HWND const window);
bool quit_on_close_ = false;
// window handle for top level window.
HWND window_handle_ = nullptr;
// window handle for hosted content.
HWND child_content_ = nullptr;
};
#endif // RUNNER_WIN32_WINDOW_H_