refactor ImgGraphicContext samples, so they can be used for test coverage

samples_test.go

@@ -0,0 +1,49 @@
+package draw2d_test
+
+import (
+	"image"
+	"testing"
+
+	"github.com/stanim/draw2d"
+
+	"github.com/stanim/draw2d.samples"
+	"github.com/stanim/draw2d.samples/android"
+	"github.com/stanim/draw2d.samples/frameimage"
+	"github.com/stanim/draw2d.samples/gopher"
+	"github.com/stanim/draw2d.samples/helloworld"
+)
+
+func test(t *testing.T, draw draw2d.Sample) {
+	// Initialize the graphic context on an RGBA image
+	dest := image.NewRGBA(image.Rect(0, 0, 297, 210.0))
+	gc := draw2d.NewGraphicContext(dest)
+	// Draw Android logo
+	fn, err := draw(gc, "png")
+	if err != nil {
+		t.Errorf("Drawing %q failed: %v", fn, err)
+		return
+	}
+	// Save to png
+	err = draw2d.SaveToPngFile(fn, dest)
+	if err != nil {
+		t.Errorf("Saving %q failed: %v", fn, err)
+	}
+}
+
+func TestSampleAndroid(t *testing.T) {
+	test(t, android.Main)
+}
+
+func TestSampleGopher(t *testing.T) {
+	test(t, gopher.Main)
+}
+
+func TestSampleHelloWorld(t *testing.T) {
+	// Set the global folder for searching fonts
+	draw2d.SetFontFolder(samples.Dir("helloworld", ""))
+	test(t, helloworld.Main)
+}
+
+func TestSampleFrameImage(t *testing.T) {
+	test(t, frameimage.Main)
+}