Create image manager and related stuff

backends/x/factory.go

@@ -19,8 +19,9 @@ import "github.com/flopp/go-findfont"
 
 // factory instantiates an X backend.
 func factory (
-	application *stone.Application,
+	application     *stone.Application,
 	callbackManager *stone.CallbackManager,
+	imageManager    *stone.ImageManager,
 ) (
 	output stone.Backend,
 	err error,
@@ -29,6 +30,7 @@ func factory (
 		application:     application,
 		config:          application.Config(),
 		callbackManager: callbackManager,
+		imageManager:    imageManager,
 	}
 
 	// load font

backends/x/x.go

@@ -17,6 +17,7 @@ type Backend struct {
 	application     *stone.Application
 	config          *stone.Config
 	callbackManager *stone.CallbackManager
+	imageManager    *stone.ImageManager
 	connection      *xgbutil.XUtil
 	window          *xwindow.Window
 	canvas          *xgraphics.Image
@@ -88,6 +89,12 @@ func (backend *Backend) SetIcon (icons []image.Image) (err error) {
 	return
 }
 
+func (backend *Backend) CellMetrics () (width, height int) {
+	width  = backend.metrics.cellWidth
+	height = backend.metrics.cellHeight
+	return
+}
+
 // calculateWindowSize calculates window bounds based on the internal buffer
 // size.
 func (backend *Backend) calculateWindowSize () (x, y int) {