cardboard-sikuli/screencap.go

package main

import (
	"bytes"
	"fmt"
	"image"
	"image/draw"
	"image/png"
	"os"
	"time"

	"github.com/go-vgo/robotgo"
	qt "github.com/mappu/miqt/qt6"
)

// doScreencap starts a new screen capture workflow.
func doScreencap(onGotNewScreenshot func(string, int64, int64)) {

	mw.MainWindow.Hide()

	time.Sleep(DefaultWait)

	bmp := robotgo.CaptureScreen(0)
	img := robotgo.ToImage(bmp)
	robotgo.FreeBitmap(bmp)

	mw.MainWindow.Show()

	// load image into Qt

	pngBuff := bytes.Buffer{}
	fastPnger := png.Encoder{
		CompressionLevel: png.NoCompression,
	}
	err := fastPnger.Encode(&pngBuff, img)
	if err != nil {
		qt.QMessageBox_Critical(mw.MainWindow.QWidget, "Screen capture error", err.Error())
		return
	}

	pixm := qt.NewQPixmap()
	ok := pixm.LoadFromData2(&pngBuff.Bytes()[0], uint(pngBuff.Len()), "png")
	if !ok {
		qt.QMessageBox_Critical(mw.MainWindow.QWidget, "Screen capture error", "PNG parse failure")
		return
	}

	pngBuff.Reset()

	//

	scWnd := NewScreenCaptureDialogUi()
	scWnd.ScreenCaptureDialog.SetModal(true)

	currentZoom := 60
	scWnd.gv.Scale(0.6, 0.6)

	scene := qt.NewQGraphicsScene6(0, 0, float64(img.Bounds().Dx()), float64(img.Bounds().Dy()), nil)
	scWnd.gv.SetScene(scene)

	scene.AddPixmap(pixm)

	rect := scene.AddRect2(0, 0, 200, 100)

	crosshair1 := scene.AddLine2(-8, -8, 8, 8)
	crosshair2 := scene.AddLine2(8, -8, -8, 8)

	isMousedown := false

	var nextStartPos *qt.QPointF

	refreshCaption := func() {
		curRect := rect.Rect()
		curPos := crosshair1.Pos()

		statusText := fmt.Sprintf("Image selection: (X=%.2f Y=%.2f W=%.2f H=%.2f) - Click offset: (X=%.2f Y=%.2f) - Zoom: %d%%",
			curRect.X(), curRect.Y(), curRect.Width(), curRect.Height(),
			curPos.X()-curRect.X(), curPos.Y()-curRect.Y(),
			currentZoom,
		)
		scWnd.lbStatus.SetText(statusText)
	}
	refreshCaption()

	scWnd.gv.OnMousePressEvent(func(super func(event *qt.QMouseEvent), event *qt.QMouseEvent) {
		pos := scWnd.gv.MapToScene(event.Pos())
		nextStartPos = pos // we'll use this pos if there is mouse movement - otherwise only move the crosshair
		isMousedown = true

		if rect.Rect().ContainsWithQPointF(pos) {
			crosshair1.SetPos(pos)
			crosshair2.SetPos(pos)
			refreshCaption()
		}

		super(event)
	})

	scWnd.gv.OnMouseMoveEvent(func(super func(event *qt.QMouseEvent), event *qt.QMouseEvent) {

		if isMousedown {
			pos := scWnd.gv.MapToScene(event.Pos())
			curRect := qt.NewQRectF4(nextStartPos.X(), nextStartPos.Y(), pos.X()-nextStartPos.X(), pos.Y()-nextStartPos.Y())
			rect.SetRect(curRect)

			crosshair1.SetPos(curRect.Center())
			crosshair2.SetPos(curRect.Center())

			refreshCaption()
		}

		super(event)
	})

	scWnd.gv.OnMouseReleaseEvent(func(super func(event *qt.QMouseEvent), event *qt.QMouseEvent) {
		isMousedown = false
		super(event)
	})

	refreshZoom := func() {
		scWnd.gv.ResetTransform()
		zScale := float64(currentZoom) / 100
		scWnd.gv.Scale(zScale, zScale)
		refreshCaption()
	}

	scWnd.btZoomIn.OnClicked(func() {
		currentZoom += 10
		refreshZoom()
	})

	scWnd.btZoomOut.OnClicked(func() {
		if currentZoom < 15 {
			return
		}

		currentZoom -= 10
		refreshZoom()
	})

	scWnd.btZoomFit.OnClicked(func() {
		currentZoom = 60
		refreshZoom()
	})

	scWnd.btCapture.OnClicked(func() {

		// Create a new image cropped to target selection

		curRect := rect.Rect()
		clickPos := crosshair1.Pos()

		imRect := image.Rectangle{
			Min: image.Point{
				X: int(curRect.X()),
				Y: int(curRect.Y()),
			},
			Max: image.Point{
				X: int(curRect.X() + curRect.Width()),
				Y: int(curRect.Y() + curRect.Height()),
			},
		}
		result := image.NewRGBA(imRect)
		draw.Draw(result, imRect, img, imRect.Min, draw.Src)

		// Encode and save as a file in the current directory
		filepath := fmt.Sprintf("%d.png", time.Now().UnixMicro())
		fh, err := os.OpenFile(filepath, os.O_CREATE|os.O_RDWR, 0644)
		if err != nil {
			panic(err)
		}

		err = png.Encode(fh, result)
		if err != nil {
			panic(err)
		}

		fh.Close()

		// Finished - close dialog and signal back to parent
		onGotNewScreenshot(filepath, int64(clickPos.X()-curRect.X()), int64(clickPos.Y()-curRect.Y()))
		scWnd.ScreenCaptureDialog.Close()
	})

	scWnd.ScreenCaptureDialog.ShowMaximized()
}