Add layout system and file selection logic

Introduce a new layout system for managing main window content and tabs. Integrate file selection and drag-and-drop functionality for adding files to the conversion list, with automatic tab switching to "Added Files". Refactor existing components to support these features.

internal/gui/view/convertor.go

@@ -1,14 +1,24 @@
 package view
 
 import (
+	"errors"
 	"fyne.io/fyne/v2"
+	"fyne.io/fyne/v2/canvas"
 	"fyne.io/fyne/v2/container"
 	"fyne.io/fyne/v2/lang"
+	"fyne.io/fyne/v2/storage"
 	"fyne.io/fyne/v2/widget"
+	"git.kor-elf.net/kor-elf/gui-for-ffmpeg/internal/ffmpeg"
+	"git.kor-elf.net/kor-elf/gui-for-ffmpeg/internal/gui/window"
+	"git.kor-elf.net/kor-elf/gui-for-ffmpeg/internal/utils"
+	"git.kor-elf.net/kor-elf/gui-for-ffmpeg/kernel"
+	"image/color"
+	"os"
+	"path/filepath"
 )
 
-func Convertor() fyne.CanvasObject {
-	form := newFormConvertor()
+func Convertor(window window.WindowContract, addFileForConversion func(file ffmpeg.File)) fyne.CanvasObject {
+	form := newFormConvertor(window, addFileForConversion)
 
 	converterVideoFilesTitle := lang.L("converterVideoFilesTitle")
 	return widget.NewCard(converterVideoFilesTitle, "", container.NewVScroll(form.getForm()))
@@ -17,17 +27,146 @@ func Convertor() fyne.CanvasObject {
 type formConvertor struct {
 	form  *widget.Form
 	items []*widget.FormItem
+
+	window               window.WindowContract
+	addFileForConversion func(file ffmpeg.File)
 }
 
-func newFormConvertor() *formConvertor {
+func newFormConvertor(window window.WindowContract, addFileForConversion func(file ffmpeg.File)) *formConvertor {
 	f := widget.NewForm()
 	f.SubmitText = lang.L("converterVideoFilesSubmitTitle")
 
-	return &formConvertor{
-		form: f,
+	formConvertor := &formConvertor{
+		form:                 f,
+		window:               window,
+		addFileForConversion: addFileForConversion,
 	}
+
+	fileForConversion := formConvertor.newFileForConversion()
+
+	items := []*widget.FormItem{
+		{
+			Text:   lang.L("fileForConversionTitle"),
+			Widget: fileForConversion.button,
+		},
+		{
+			Widget: container.NewHScroll(fileForConversion.message),
+		},
+	}
+	formConvertor.form.Items = items
+	formConvertor.items = items
+
+	return formConvertor
 }
 
 func (f *formConvertor) getForm() *widget.Form {
 	return f.form
 }
+
+type fileForConversion struct {
+	button  *widget.Button
+	message *canvas.Text
+	file    *kernel.File
+
+	changeCallbacks map[int]func(err error)
+}
+
+func (f *formConvertor) newFileForConversion() *fileForConversion {
+	message := canvas.NewText("", color.RGBA{R: 255, G: 0, B: 0, A: 255})
+	fileForConversion := &fileForConversion{
+		message: message,
+
+		changeCallbacks: map[int]func(err error){},
+	}
+
+	buttonTitle := lang.L("choose") + "\n" +
+		lang.L("or") + "\n" +
+		lang.L("dragAndDropFiles")
+
+	var locationURI fyne.ListableURI
+
+	fileForConversion.button = widget.NewButton(buttonTitle, func() {
+		f.window.NewFileOpen(func(r fyne.URIReadCloser, err error) {
+			fyne.Do(func() {
+				fileForConversion.message.Text = ""
+				fileForConversion.message.Refresh()
+			})
+
+			if err != nil {
+				fyne.Do(func() {
+					fileForConversion.message.Text = err.Error()
+					fileForConversion.message.Refresh()
+				})
+				fileForConversion.eventSelectFile(err)
+				return
+			}
+			if r == nil {
+				return
+			}
+
+			f.addFileForConversion(ffmpeg.File{
+				Path: r.URI().Path(),
+				Name: r.URI().Name(),
+				Ext:  r.URI().Extension(),
+			})
+
+			fileForConversion.eventSelectFile(nil)
+
+			listableURI := storage.NewFileURI(filepath.Dir(r.URI().Path()))
+			locationURI, _ = storage.ListerForURI(listableURI)
+		}, locationURI)
+	})
+
+	f.window.SetOnDropped(func(position fyne.Position, uris []fyne.URI) {
+		if len(uris) == 0 {
+			return
+		}
+
+		isError := false
+		for _, uri := range uris {
+			info, err := os.Stat(uri.Path())
+			if err != nil {
+				isError = true
+				continue
+			}
+			if info.IsDir() {
+				isError = true
+				continue
+			}
+
+			f.addFileForConversion(ffmpeg.File{
+				Path: uri.Path(),
+				Name: uri.Name(),
+				Ext:  uri.Extension(),
+			})
+
+			fileForConversion.eventSelectFile(nil)
+
+			listableURI := storage.NewFileURI(filepath.Dir(uri.Path()))
+			locationURI, _ = storage.ListerForURI(listableURI)
+		}
+
+		if isError {
+			fileForConversion.message.Text = lang.L("errorDragAndDropFile")
+			utils.SetStringErrorStyle(fileForConversion.message)
+			fileForConversion.eventSelectFile(errors.New(fileForConversion.message.Text))
+		} else {
+			fyne.Do(func() {
+				fileForConversion.message.Text = ""
+				fileForConversion.message.Refresh()
+			})
+		}
+	})
+
+	return fileForConversion
+}
+
+func (c *fileForConversion) addChangeCallback(callback func(err error)) {
+	c.changeCallbacks[len(c.changeCallbacks)] = callback
+}
+
+func (c *fileForConversion) eventSelectFile(err error) {
+	for _, changeCallback := range c.changeCallbacks {
+		changeCallback(err)
+	}
+}