MasterWindow.go

package giu

import (
	"errors"
	"image"
	"image/color"
	"runtime"

	imgui "github.com/AllenDang/cimgui-go"
	"golang.org/x/image/colornames"
)

// MasterWindowFlags implements BackendWindowFlags.
type MasterWindowFlags int

// master window flags.
const (
	// Specifies the window will be fixed size.
	MasterWindowFlagsNotResizable MasterWindowFlags = 1 << iota
	// Specifies whether the window is maximized.
	MasterWindowFlagsMaximized
	// Specifies whether the window will be always-on-top.
	MasterWindowFlagsFloating
	// Specifies whether the window will be frameless.
	MasterWindowFlagsFrameless
	// Specifies whether the window will be transparent.
	MasterWindowFlagsTransparent
)

// parseAndApply converts MasterWindowFlags to appropriate imgui.GLFWWindowFlags.
func (m MasterWindowFlags) parseAndApply(b imgui.Backend[imgui.GLFWWindowFlags]) {
	data := map[MasterWindowFlags]struct {
		f     imgui.GLFWWindowFlags
		value int // value isn't always true (sometimes false). Also WindowHint takes int not bool
	}{
		MasterWindowFlagsNotResizable: {imgui.GLFWWindowFlagsResizable, 0},
		MasterWindowFlagsMaximized:    {imgui.GLFWWindowFlagsMaximized, 1},
		MasterWindowFlagsFloating:     {imgui.GLFWWindowFlagsFloating, 1},
		MasterWindowFlagsFrameless:    {imgui.GLFWWindowFlagsDecorated, 0},
		MasterWindowFlagsTransparent:  {imgui.GLFWWindowFlagsTransparent, 1},
	}

	for flag, d := range data {
		if m&flag != 0 {
			b.SetWindowFlags(d.f, d.value)
		}
	}
}

// TODO(gucio321) implement this in cimgui-go
// DontCare could be used as an argument to (*MasterWindow).SetSizeLimits.
// var DontCare int = imgui.GlfwDontCare

// MasterWindow represents a glfw master window
// It is a base for a windows (see Window.go).
type MasterWindow struct {
	backend imgui.Backend[imgui.GLFWWindowFlags]

	width      int
	height     int
	clearColor imgui.Vec4
	title      string
	context    *imgui.Context
	io         *imgui.IO
	updateFunc func()

	// possibility to expend InputHandler's stuff
	// See SetAdditionalInputHandler
	additionalInputCallback InputHandlerHandleCallback
}

// NewMasterWindow creates a new master window and initializes GLFW.
// it should be called in main function. For more details and use cases,
// see examples/helloworld/.
func NewMasterWindow(title string, width, height int, flags MasterWindowFlags) *MasterWindow {
	imGuiContext := imgui.CreateContext()
	imgui.PlotCreateContext()
	imgui.ImNodesCreateContext()

	io := imgui.CurrentIO()

	// TODO: removed ConfigFlagEnablePowerSavingMode
	// TODO: removed io.SetConfigFlags(imgui.BackendFlagsRendererHasVtxOffset)
	io.SetBackendFlags(imgui.BackendFlagsRendererHasVtxOffset)

	// Disable imgui.ini
	io.SetIniFilename("")

	backend, err := imgui.CreateBackend(imgui.NewGLFWBackend())
	if err != nil && !errors.Is(err, imgui.CExposerError) {
		panic(err)
	}

	// Create GIU context
	Context = CreateContext(backend)

	mw := &MasterWindow{
		clearColor: imgui.Vec4{X: 0, Y: 0, Z: 0, W: 1},
		width:      width,
		height:     height,
		title:      title,
		io:         io,
		context:    imGuiContext,
		backend:    backend,
	}

	backend.SetBeforeRenderHook(mw.beforeRender)
	backend.SetAfterRenderHook(mw.afterRender)
	backend.SetBeforeDestroyContextHook(mw.beforeDestroy)
	flags.parseAndApply(backend)
	backend.CreateWindow(title, width, height)

	mw.SetInputHandler(newInputHandler())

	mw.backend.SetSizeChangeCallback(mw.sizeChange)

	mw.SetBgColor(colornames.Black)

	return mw
}

func (w *MasterWindow) setTheme() (fin func()) {
	// Scale DPI in windows
	if runtime.GOOS == "windows" {
		xScale, _ := Context.backend.ContentScale()
		imgui.CurrentStyle().ScaleAllSizes(xScale)
	}

	imgui.PushStyleVarFloat(imgui.StyleVarWindowRounding, 2)
	imgui.PushStyleVarFloat(imgui.StyleVarFrameRounding, 4)
	imgui.PushStyleVarFloat(imgui.StyleVarGrabRounding, 4)
	imgui.PushStyleVarFloat(imgui.StyleVarFrameBorderSize, 1)

	imgui.PushStyleColorVec4(imgui.ColText, imgui.Vec4{X: 0.95, Y: 0.96, Z: 0.98, W: 1.00})
	imgui.PushStyleColorVec4(imgui.ColTextDisabled, imgui.Vec4{X: 0.36, Y: 0.42, Z: 0.47, W: 1.00})
	imgui.PushStyleColorVec4(imgui.ColWindowBg, imgui.Vec4{X: 0.11, Y: 0.15, Z: 0.17, W: 1.00})
	imgui.PushStyleColorVec4(imgui.ColChildBg, imgui.Vec4{X: 0.15, Y: 0.18, Z: 0.22, W: 1.00})
	imgui.PushStyleColorVec4(imgui.ColPopupBg, imgui.Vec4{X: 0.08, Y: 0.08, Z: 0.08, W: 0.94})
	imgui.PushStyleColorVec4(imgui.ColBorder, imgui.Vec4{X: 0.08, Y: 0.10, Z: 0.12, W: 1.00})
	imgui.PushStyleColorVec4(imgui.ColBorderShadow, imgui.Vec4{X: 0.00, Y: 0.00, Z: 0.00, W: 0.00})
	imgui.PushStyleColorVec4(imgui.ColFrameBg, imgui.Vec4{X: 0.20, Y: 0.25, Z: 0.29, W: 1.00})
	imgui.PushStyleColorVec4(imgui.ColFrameBgHovered, imgui.Vec4{X: 0.12, Y: 0.20, Z: 0.28, W: 1.00})
	imgui.PushStyleColorVec4(imgui.ColFrameBgActive, imgui.Vec4{X: 0.09, Y: 0.12, Z: 0.14, W: 1.00})
	imgui.PushStyleColorVec4(imgui.ColTitleBg, imgui.Vec4{X: 0.09, Y: 0.12, Z: 0.14, W: 0.65})
	imgui.PushStyleColorVec4(imgui.ColTitleBgActive, imgui.Vec4{X: 0.08, Y: 0.10, Z: 0.12, W: 1.00})
	imgui.PushStyleColorVec4(imgui.ColTitleBgCollapsed, imgui.Vec4{X: 0.00, Y: 0.00, Z: 0.00, W: 0.51})
	imgui.PushStyleColorVec4(imgui.ColMenuBarBg, imgui.Vec4{X: 0.15, Y: 0.18, Z: 0.22, W: 1.00})
	imgui.PushStyleColorVec4(imgui.ColScrollbarBg, imgui.Vec4{X: 0.02, Y: 0.02, Z: 0.02, W: 0.39})
	imgui.PushStyleColorVec4(imgui.ColScrollbarGrab, imgui.Vec4{X: 0.20, Y: 0.25, Z: 0.29, W: 1.00})
	imgui.PushStyleColorVec4(imgui.ColScrollbarGrabHovered, imgui.Vec4{X: 0.18, Y: 0.22, Z: 0.25, W: 1.00})
	imgui.PushStyleColorVec4(imgui.ColScrollbarGrabActive, imgui.Vec4{X: 0.09, Y: 0.21, Z: 0.31, W: 1.00})
	imgui.PushStyleColorVec4(imgui.ColCheckMark, imgui.Vec4{X: 0.28, Y: 0.56, Z: 1.00, W: 1.00})
	imgui.PushStyleColorVec4(imgui.ColSliderGrab, imgui.Vec4{X: 0.28, Y: 0.56, Z: 1.00, W: 1.00})
	imgui.PushStyleColorVec4(imgui.ColSliderGrabActive, imgui.Vec4{X: 0.37, Y: 0.61, Z: 1.00, W: 1.00})
	imgui.PushStyleColorVec4(imgui.ColButton, imgui.Vec4{X: 0.20, Y: 0.25, Z: 0.29, W: 1.00})
	imgui.PushStyleColorVec4(imgui.ColButtonHovered, imgui.Vec4{X: 0.28, Y: 0.56, Z: 1.00, W: 1.00})
	imgui.PushStyleColorVec4(imgui.ColButtonActive, imgui.Vec4{X: 0.06, Y: 0.53, Z: 0.98, W: 1.00})
	imgui.PushStyleColorVec4(imgui.ColHeader, imgui.Vec4{X: 0.20, Y: 0.25, Z: 0.29, W: 0.55})
	imgui.PushStyleColorVec4(imgui.ColHeaderHovered, imgui.Vec4{X: 0.26, Y: 0.59, Z: 0.98, W: 0.80})
	imgui.PushStyleColorVec4(imgui.ColHeaderActive, imgui.Vec4{X: 0.26, Y: 0.59, Z: 0.98, W: 1.00})
	imgui.PushStyleColorVec4(imgui.ColSeparator, imgui.Vec4{X: 0.20, Y: 0.25, Z: 0.29, W: 1.00})
	imgui.PushStyleColorVec4(imgui.ColSeparatorHovered, imgui.Vec4{X: 0.10, Y: 0.40, Z: 0.75, W: 0.78})
	imgui.PushStyleColorVec4(imgui.ColSeparatorActive, imgui.Vec4{X: 0.10, Y: 0.40, Z: 0.75, W: 1.00})
	imgui.PushStyleColorVec4(imgui.ColResizeGrip, imgui.Vec4{X: 0.26, Y: 0.59, Z: 0.98, W: 0.25})
	imgui.PushStyleColorVec4(imgui.ColResizeGripHovered, imgui.Vec4{X: 0.26, Y: 0.59, Z: 0.98, W: 0.67})
	imgui.PushStyleColorVec4(imgui.ColResizeGripActive, imgui.Vec4{X: 0.26, Y: 0.59, Z: 0.98, W: 0.95})
	imgui.PushStyleColorVec4(imgui.ColTab, imgui.Vec4{X: 0.11, Y: 0.15, Z: 0.17, W: 1.00})
	imgui.PushStyleColorVec4(imgui.ColTabHovered, imgui.Vec4{X: 0.26, Y: 0.59, Z: 0.98, W: 0.80})
	imgui.PushStyleColorVec4(imgui.ColTabActive, imgui.Vec4{X: 0.20, Y: 0.25, Z: 0.29, W: 1.00})
	imgui.PushStyleColorVec4(imgui.ColTabUnfocused, imgui.Vec4{X: 0.11, Y: 0.15, Z: 0.17, W: 1.00})
	imgui.PushStyleColorVec4(imgui.ColTabUnfocusedActive, imgui.Vec4{X: 0.11, Y: 0.15, Z: 0.17, W: 1.00})
	imgui.PushStyleColorVec4(imgui.ColPlotLines, imgui.Vec4{X: 0.61, Y: 0.61, Z: 0.61, W: 1.00})
	imgui.PushStyleColorVec4(imgui.ColPlotLinesHovered, imgui.Vec4{X: 1.00, Y: 0.43, Z: 0.35, W: 1.00})
	imgui.PushStyleColorVec4(imgui.ColPlotHistogram, imgui.Vec4{X: 0.90, Y: 0.70, Z: 0.00, W: 1.00})
	imgui.PushStyleColorVec4(imgui.ColPlotHistogramHovered, imgui.Vec4{X: 1.00, Y: 0.60, Z: 0.00, W: 1.00})
	imgui.PushStyleColorVec4(imgui.ColTextSelectedBg, imgui.Vec4{X: 0.26, Y: 0.59, Z: 0.98, W: 0.35})
	imgui.PushStyleColorVec4(imgui.ColDragDropTarget, imgui.Vec4{X: 1.00, Y: 1.00, Z: 0.00, W: 0.90})
	imgui.PushStyleColorVec4(imgui.ColNavHighlight, imgui.Vec4{X: 0.26, Y: 0.59, Z: 0.98, W: 1.00})
	imgui.PushStyleColorVec4(imgui.ColNavWindowingHighlight, imgui.Vec4{X: 1.00, Y: 1.00, Z: 1.00, W: 0.70})
	imgui.PushStyleColorVec4(imgui.ColTableHeaderBg, imgui.Vec4{X: 0.12, Y: 0.20, Z: 0.28, W: 1.00})
	imgui.PushStyleColorVec4(imgui.ColTableBorderStrong, imgui.Vec4{X: 0.20, Y: 0.25, Z: 0.29, W: 1.00})
	imgui.PushStyleColorVec4(imgui.ColTableBorderLight, imgui.Vec4{X: 0.20, Y: 0.25, Z: 0.29, W: 0.70})

	return func() {
		imgui.PopStyleColorV(49)
		imgui.PopStyleVarV(4)
	}
}

func (w *MasterWindow) sizeChange(width, height int) {
	// noop
}

func (w *MasterWindow) beforeRender() {
	Context.invalidAllState()
	Context.FontAtlas.rebuildFontAtlas()

	// process texture load requests
	if Context.textureLoadingQueue != nil && Context.textureLoadingQueue.Length() > 0 {
		for Context.textureLoadingQueue.Length() > 0 {
			request, ok := Context.textureLoadingQueue.Remove().(textureLoadRequest)
			Assert(ok, "MasterWindow", "Run", "processing texture requests: wrong type of texture request")
			NewTextureFromRgba(request.img, request.cb)
		}
	}
}

func (w *MasterWindow) afterRender() {
	Context.cleanState()
}

func (w *MasterWindow) beforeDestroy() {
	imgui.PlotDestroyContext()
	imgui.ImNodesDestroyContext()
}

func (w *MasterWindow) render() {
	fin := w.setTheme()
	defer fin()

	mainStylesheet := Style()
	if s, found := Context.cssStylesheet["main"]; found {
		mainStylesheet = s
	}

	mainStylesheet.Push()
	w.updateFunc()
	mainStylesheet.Pop()
}

// Run runs the main loop.
// loopFunc will be used to construct the ui.
// Run should be called at the end of main function, after setting
// up the master window.
func (w *MasterWindow) Run(loopFunc func()) {
	mainthreadCallPlatform(func() {
		Context.isRunning = true
		w.updateFunc = loopFunc

		Context.m.Lock()
		Context.isAlive = true
		Context.m.Unlock()

		Context.backend.Run(w.render)

		Context.m.Lock()
		Context.isAlive = false

		Context.isRunning = false
		Context.m.Unlock()
	})
}

// GetSize return size of master window.
func (w *MasterWindow) GetSize() (width, height int) {
	if w.backend != nil {
		w, h := w.backend.DisplaySize()
		return int(w), int(h)
	}

	return w.width, w.height
}

// SetBgColor sets background color of master window.
func (w *MasterWindow) SetBgColor(bgColor color.Color) {
	const mask = 0xffff

	r, g, b, a := bgColor.RGBA()
	w.clearColor = imgui.Vec4{
		X: float32(r) / mask,
		Y: float32(g) / mask,
		Z: float32(b) / mask,
		W: float32(a) / mask,
	}

	w.backend.SetBgColor(w.clearColor)
}

// SetTargetFPS sets target FPS of master window.
// Default for GLFW is 30.
func (w *MasterWindow) SetTargetFPS(fps uint) {
	w.backend.SetTargetFPS(fps)
}

// GetPos return position of master window.
func (w *MasterWindow) GetPos() (x, y int) {
	var xResult, yResult int32
	if w.backend != nil {
		xResult, yResult = w.backend.GetWindowPos()
	}

	return int(xResult), int(yResult)
}

// SetPos sets position of master window.
func (w *MasterWindow) SetPos(x, y int) {
	if w.backend != nil {
		w.backend.SetWindowPos(x, y)
	}
}

// SetSize sets size of master window.
func (w *MasterWindow) SetSize(x, y int) {
	if w.backend != nil {
		w.backend.SetWindowSize(x, y)
	}
}

// SetCloseCallback sets the close callback of the window, which is called when
// the user attempts to close the window, for example by clicking the close
// widget in the title bar.
//
// The close flag is set before this callback is called, but you can modify it at
// any time with returned value of callback function.
//
// Mac OS X: Selecting Quit from the application menu will trigger the close
// callback for all windows.
func (w *MasterWindow) SetCloseCallback(cb func() bool) {
	w.backend.SetCloseCallback(func(b imgui.Backend[imgui.GLFWWindowFlags]) {
		b.SetShouldClose(cb())
	})
}

// SetDropCallback sets callback when file was dropped into the window.
func (w *MasterWindow) SetDropCallback(cb func([]string)) {
	w.backend.SetDropCallback(cb)
}

// RegisterKeyboardShortcuts registers a global - master window - keyboard shortcuts.
func (w *MasterWindow) RegisterKeyboardShortcuts(s ...WindowShortcut) *MasterWindow {
	for _, shortcut := range s {
		Context.InputHandler.RegisterKeyboardShortcuts(Shortcut{
			Key:      shortcut.Key,
			Modifier: shortcut.Modifier,
			Callback: shortcut.Callback,
			IsGlobal: GlobalShortcut,
		})
	}

	return w
}

// SetIcon sets the icon of the specified window. If passed an array of candidate images,
// those of or closest to the sizes desired by the system are selected. If no images are
// specified, the window reverts to its default icon.
//
// The image is ideally provided in the form of *image.NRGBA.
// The pixels are 32-bit, little-endian, non-premultiplied RGBA, i.e. eight
// bits per channel with the red channel first. They are arranged canonically
// as packed sequential rows, starting from the top-left corner. If the image
// type is not *image.NRGBA, it will be converted to it.
//
// The desired image sizes varies depending on platform and system settings. The selected
// images will be rescaled as needed. Good sizes include 16x16, 32x32 and 48x48.
func (w *MasterWindow) SetIcon(icons ...image.Image) {
	w.backend.SetIcons(icons...)
}

// SetSizeLimits sets the size limits of the client area of the specified window.
// If the window is full screen or not resizable, this function does nothing.
//
// The size limits are applied immediately and may cause the window to be resized.
// To specify only a minimum size or only a maximum one, set the other pair to giu.DontCare.
// To disable size limits for a window, set them all to giu.DontCare.
func (w *MasterWindow) SetSizeLimits(minw, minh, maxw, maxh int) {
	w.backend.SetWindowSizeLimits(minw, minh, maxw, maxh)
}

// SetTitle updates master window's title.
func (w *MasterWindow) SetTitle(title string) {
	w.backend.SetWindowTitle(title)
}

// Close will safely close the master window.
func (w *MasterWindow) Close() {
	w.SetShouldClose(true)
}

// SetShouldClose sets whether master window should be closed.
func (w *MasterWindow) SetShouldClose(v bool) {
	w.backend.SetShouldClose(v)
}

// SetInputHandler allows to change default input handler.
// see InputHandler.go.
func (w *MasterWindow) SetInputHandler(handler InputHandler) {
	Context.InputHandler = handler

	w.backend.SetKeyCallback(func(key, scanCode, action, modifier int) {
		k, m, a := keyFromGLFWKey(imgui.GLFWKey(key)), Modifier(modifier), Action(action)
		handler.Handle(k, m, a)

		if w.additionalInputCallback != nil {
			w.additionalInputCallback(k, m, a)
		}
	})
}

// SetAdditionalInputHandlerCallback allows to set an input callback to handle more events (not only these from giu.inputHandler).
// See examples/issue-501.
func (w *MasterWindow) SetAdditionalInputHandlerCallback(cb InputHandlerHandleCallback) {
	w.additionalInputCallback = cb
}