Fixed wierd inconsistency with element core

elements/basic/textbox.go

@@ -257,7 +257,7 @@ func (element *TextBox) runOnChange () {
 func (element *TextBox) scrollToCursor () {
 	if !element.core.HasImage() { return }
 
-	bounds := element.core.Bounds().Inset(theme.Padding())
+	bounds := element.Bounds().Inset(theme.Padding())
 	bounds.Max.X -= element.valueDrawer.Em().Round()
 	cursorPosition := element.valueDrawer.PositionOf(element.cursor)
 	cursorPosition.X -= element.scroll
@@ -272,7 +272,7 @@ func (element *TextBox) scrollToCursor () {
 }
 
 func (element *TextBox) draw () {
-	bounds := element.core.Bounds()
+	bounds := element.Bounds()
 
 	// FIXME: take index into account
 	pattern, inset := theme.InputPattern(theme.PatternState {
@@ -280,7 +280,7 @@ func (element *TextBox) draw () {
 		Disabled: !element.Enabled(),
 		Focused:  element.Focused(),
 	})
-	artist.FillRectangle(element.core, pattern, bounds)
+	artist.FillRectangle(element, pattern, bounds)
 
 	if len(element.text) == 0 && !element.Focused() {
 		// draw placeholder
@@ -294,7 +294,7 @@ func (element *TextBox) draw () {
 			Disabled: true,
 		})
 		element.placeholderDrawer.Draw (
-			element.core,
+			element,
 			foreground,
 			offset.Sub(textBounds.Min))
 	} else {
@@ -309,7 +309,7 @@ func (element *TextBox) draw () {
 			Disabled: !element.Enabled(),
 		})
 		element.valueDrawer.Draw (
-			element.core,
+			element,
 			foreground,
 			offset.Sub(textBounds.Min))
 
@@ -321,7 +321,7 @@ func (element *TextBox) draw () {
 				Case: textBoxCase,
 			})
 			artist.Line (
-				element.core,
+				element,
 				foreground, 1,
 				cursorPosition.Add(offset),
 				image.Pt (