Add tests for file dialog filtering.

dialog/file.go

@@ -308,6 +308,7 @@ func showFileDialog(save bool, callback interface{}, parent fyne.Window, filter
 func (fd *FileDialog) SetFilter(filter FileFilter) {
 	fd.filter = filter
 	if fd.dialog != nil {
+		fd.dialog.filter = filter
 		fd.dialog.refreshDir(fd.dialog.dir)
 	}
 }

dialog/file_test.go

@@ -4,11 +4,13 @@ import (
 	"log"
 	"os"
 	"path/filepath"
+	"strings"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
 
 	"fyne.io/fyne"
+	"fyne.io/fyne/storage"
 	"fyne.io/fyne/test"
 	"fyne.io/fyne/widget"
 )
@@ -133,3 +135,56 @@ func TestShowFileSave(t *testing.T) {
 	err = os.Remove(expectedPath)
 	assert.Nil(t, err)
 }
+
+func TestFileFilters(t *testing.T) {
+	win := test.NewWindow(widget.NewLabel("Content"))
+	fd := NewFileOpenDialog(func(file fyne.FileReadCloser, err error) {
+	}, win)
+
+	fd.SetFilter(NewExtensionFileFilter([]string{".png"}))
+	fd.Show()
+
+	workingDir, err := os.Getwd()
+	if err != nil {
+		fyne.LogError("Could not get current working directory", err)
+		t.FailNow()
+	}
+	testDataDir := filepath.Join(workingDir, "testdata")
+
+	fd.dialog.setDirectory(testDataDir)
+
+	count := 0
+	for _, icon := range fd.dialog.files.Objects {
+		if icon.(*fileDialogItem).dir == false {
+			uri := storage.NewURI(icon.(*fileDialogItem).path)
+			assert.Equal(t, uri.Extension(), ".png")
+			count++
+		}
+	}
+	assert.Equal(t, count, 1)
+
+	fd.SetFilter(NewMimeTypeFileFilter([]string{"image/jpeg"}))
+
+	count = 0
+	for _, icon := range fd.dialog.files.Objects {
+		if icon.(*fileDialogItem).dir == false {
+			uri := storage.NewURI(icon.(*fileDialogItem).path)
+			assert.Equal(t, uri.MimeType(), "image/jpeg")
+			count++
+		}
+	}
+	assert.Equal(t, count, 1)
+
+	fd.SetFilter(NewMimeTypeFileFilter([]string{"image/*"}))
+
+	count = 0
+	for _, icon := range fd.dialog.files.Objects {
+		if icon.(*fileDialogItem).dir == false {
+			uri := storage.NewURI(icon.(*fileDialogItem).path)
+			mimeType := strings.Split(uri.MimeType(), "/")[0]
+			assert.Equal(t, mimeType, "image")
+			count++
+		}
+	}
+	assert.Equal(t, count, 2)
+}

dialog/testdata/test.txt

@@ -0,0 +1 @@
+test