waveshare213v2: Move error handler to separate file

The structure definition and the functions were already split up. Moving
to a separate file simplifies the code structure.

Signed-off-by: Michael Hanselmann <public@hansmi.ch>

waveshare2in13v2/errorhandler.go

@@ -0,0 +1,55 @@
+// Copyright 2021 The Periph Authors. All rights reserved.
+// Use of this source code is governed under the Apache License, Version 2.0
+// that can be found in the LICENSE file.
+
+package waveshare2in13v2
+
+import "periph.io/x/conn/v3/gpio"
+
+// errorHandler is a wrapper for error management.
+type errorHandler struct {
+	d   Dev
+	err error
+}
+
+func (eh *errorHandler) rstOut(l gpio.Level) {
+	if eh.err != nil {
+		return
+	}
+	eh.err = eh.d.rst.Out(l)
+}
+
+func (eh *errorHandler) cTx(w []byte, r []byte) {
+	if eh.err != nil {
+		return
+	}
+	eh.err = eh.d.c.Tx(w, r)
+}
+
+func (eh *errorHandler) dcOut(l gpio.Level) {
+	if eh.err != nil {
+		return
+	}
+	eh.err = eh.d.dc.Out(l)
+}
+
+func (eh *errorHandler) csOut(l gpio.Level) {
+	if eh.err != nil {
+		return
+	}
+	eh.err = eh.d.cs.Out(l)
+}
+
+func (eh *errorHandler) sendCommand(cmd byte) {
+	if eh.err != nil {
+		return
+	}
+	eh.err = eh.d.sendCommand(cmd)
+}
+
+func (eh *errorHandler) sendData(d []byte) {
+	if eh.err != nil {
+		return
+	}
+	eh.err = eh.d.sendData(d)
+}

waveshare2in13v2/waveshare213v2.go

@@ -81,12 +81,6 @@ type Opts struct {
 // PartialUpdate defines if the display should do a full update or just a partial update.
 type PartialUpdate bool
 
-// errorHandler is a wrapper for error management.
-type errorHandler struct {
-	d   Dev
-	err error
-}
-
 const (
 	// Full should update the complete display.
 	Full PartialUpdate = false
@@ -136,48 +130,6 @@ func dataDimensions(opts *Opts) (int, int) {
 	return opts.Height, (opts.Width + 7) / 8
 }
 
-func (eh *errorHandler) rstOut(l gpio.Level) {
-	if eh.err != nil {
-		return
-	}
-	eh.err = eh.d.rst.Out(l)
-}
-
-func (eh *errorHandler) cTx(w []byte, r []byte) {
-	if eh.err != nil {
-		return
-	}
-	eh.err = eh.d.c.Tx(w, r)
-}
-
-func (eh *errorHandler) dcOut(l gpio.Level) {
-	if eh.err != nil {
-		return
-	}
-	eh.err = eh.d.dc.Out(l)
-}
-
-func (eh *errorHandler) csOut(l gpio.Level) {
-	if eh.err != nil {
-		return
-	}
-	eh.err = eh.d.cs.Out(l)
-}
-
-func (eh *errorHandler) sendCommand(cmd byte) {
-	if eh.err != nil {
-		return
-	}
-	eh.err = eh.d.sendCommand(cmd)
-}
-
-func (eh *errorHandler) sendData(d []byte) {
-	if eh.err != nil {
-		return
-	}
-	eh.err = eh.d.sendData(d)
-}
-
 // New creates new handler which is used to access the display.
 func New(p spi.Port, dc, cs, rst gpio.PinOut, busy gpio.PinIO, opts *Opts) (*Dev, error) {
 	c, err := p.Connect(5*physic.MegaHertz, spi.Mode0, 8)