Fix/scrolling contents

runtime/ui/view/cursor.go

@@ -1,38 +1,17 @@
 package view
 
 import (
-	"errors"
-
 	"github.com/awesome-gocui/gocui"
 )
 
 // CursorDown moves the cursor down in the currently selected gocui pane, scrolling the screen as needed.
-func CursorDown(g *gocui.Gui, v *gocui.View) error {
-	return CursorStep(g, v, 1)
+func CursorDown(v *gocui.View, step uint) error {
+	v.MoveCursor(0, int(step))
+	return nil
 }
 
 // CursorUp moves the cursor up in the currently selected gocui pane, scrolling the screen as needed.
-func CursorUp(g *gocui.Gui, v *gocui.View) error {
-	return CursorStep(g, v, -1)
-}
-
-// Moves the cursor the given step distance, setting the origin to the new cursor line
-func CursorStep(g *gocui.Gui, v *gocui.View, step int) error {
-	cx, cy := v.Cursor()
-
-	// if there isn't a next line
-	line, err := v.Line(cy + step)
-	if err != nil {
-		return err
-	}
-	if len(line) == 0 {
-		return errors.New("unable to move the cursor, empty line")
-	}
-	if err := v.SetCursor(cx, cy+step); err != nil {
-		ox, oy := v.Origin()
-		if err := v.SetOrigin(ox, oy+step); err != nil {
-			return err
-		}
-	}
+func CursorUp(v *gocui.View, step uint) error {
+	v.MoveCursor(0, int(-step))
 	return nil
 }

runtime/ui/view/image_details.go

@@ -136,32 +136,20 @@ func (v *ImageDetails) IsVisible() bool {
 
 func (v *ImageDetails) PageUp() error {
 	_, height := v.body.Size()
-	if err := CursorStep(v.gui, v.body, -height); err != nil {
-		logrus.Debugf("Couldn't move the cursor up by %d steps", height)
-	}
-	return nil
+	return CursorUp(v.body, uint(height))
 }
 
 func (v *ImageDetails) PageDown() error {
 	_, height := v.body.Size()
-	if err := CursorStep(v.gui, v.body, height); err != nil {
-		logrus.Debugf("Couldn't move the cursor down by %d steps", height)
-	}
-	return nil
+	return CursorDown(v.body, uint(height))
 }
 
 func (v *ImageDetails) CursorUp() error {
-	if err := CursorUp(v.gui, v.body); err != nil {
-		logrus.Debug("Couldn't move the cursor up")
-	}
-	return nil
+	return CursorUp(v.body, 1)
 }
 
 func (v *ImageDetails) CursorDown() error {
-	if err := CursorDown(v.gui, v.body); err != nil {
-		logrus.Debug("Couldn't move the cursor down")
-	}
-	return nil
+	return CursorDown(v.body, 1)
 }
 
 // KeyHelp indicates all the possible actions a user can take while the current pane is selected (currently does nothing).

runtime/ui/view/layer.go

@@ -102,7 +102,7 @@ func (v *Layer) Setup(body *gocui.View, header *gocui.View) error {
 	v.header.Wrap = false
 	v.header.Frame = false
 
-	var infos = []key.BindingInfo{
+	infos := []key.BindingInfo{
 		{
 			ConfigKeys: []string{"keybinding.compare-layer"},
 			OnAction:   func() error { return v.setCompareMode(viewmodel.CompareSingleLayer) },
@@ -141,15 +141,15 @@ func (v *Layer) Setup(body *gocui.View, header *gocui.View) error {
 	}
 	v.helpKeys = helpKeys
 
-	return v.Render()
-}
-
-// height obtains the height of the current pane (taking into account the lost space due to the header).
-func (v *Layer) height() uint {
 	_, height := v.body.Size()
-	return uint(height - 1)
+	v.vm.Setup(0, height)
+	_ = v.Update()
+	_ = v.Render()
+
+	return nil
 }
 
+
 func (v *Layer) CompareMode() viewmodel.LayerCompareMode {
 	return v.vm.CompareMode
 }
@@ -161,62 +161,48 @@ func (v *Layer) IsVisible() bool {
 
 // PageDown moves to next page putting the cursor on top
 func (v *Layer) PageDown() error {
-	step := int(v.height()) + 1
-	targetLayerIndex := v.vm.LayerIndex + step
-
-	if targetLayerIndex > len(v.vm.Layers) {
-		step -= targetLayerIndex - (len(v.vm.Layers) - 1)
-	}
-
-	if step > 0 {
-		// err := CursorStep(v.gui, v.body, step)
-		err := error(nil)
-		if err == nil {
-			return v.SetCursor(v.vm.LayerIndex + step)
+	if v.vm.PageDown() {
+		err := v.notifyLayerChangeListeners()
+		if err != nil {
+			return err
 		}
+		return v.Render()
 	}
 	return nil
 }
 
 // PageUp moves to previous page putting the cursor on top
 func (v *Layer) PageUp() error {
-	step := int(v.height()) + 1
-	targetLayerIndex := v.vm.LayerIndex - step
-
-	if targetLayerIndex < 0 {
-		step += targetLayerIndex
-	}
-
-	if step > 0 {
-		// err := CursorStep(v.gui, v.body, -step)
-		err := error(nil)
-		if err == nil {
-			return v.SetCursor(v.vm.LayerIndex - step)
+	if v.vm.PageUp() {
+		err := v.notifyLayerChangeListeners()
+		if err != nil {
+			return err
 		}
+		return v.Render()
 	}
 	return nil
 }
 
 // CursorDown moves the cursor down in the layer pane (selecting a higher layer).
 func (v *Layer) CursorDown() error {
-	if v.vm.LayerIndex < len(v.vm.Layers)-1 {
-		// err := CursorDown(v.gui, v.body)
-		err := error(nil)
-		if err == nil {
-			return v.SetCursor(v.vm.LayerIndex + 1)
+	if v.vm.CursorDown() {
+		err := v.notifyLayerChangeListeners()
+		if err != nil {
+			return err
 		}
+		return v.Render()
 	}
 	return nil
 }
 
 // CursorUp moves the cursor up in the layer pane (selecting a lower layer).
 func (v *Layer) CursorUp() error {
-	if v.vm.LayerIndex > 0 {
-		// err := CursorUp(v.gui, v.body)
-		err := error(nil)
-		if err == nil {
-			return v.SetCursor(v.vm.LayerIndex - 1)
+	if v.vm.CursorUp() {
+		err := v.notifyLayerChangeListeners()
+		if err != nil {
+			return err
 		}
+		return v.Render()
 	}
 	return nil
 }
@@ -243,21 +229,6 @@ func (v *Layer) setCompareMode(compareMode viewmodel.LayerCompareMode) error {
 	return v.notifyLayerChangeListeners()
 }
 
-// renderCompareBar returns the formatted string for the given layer.
-func (v *Layer) renderCompareBar(layerIdx int) string {
-	bottomTreeStart, bottomTreeStop, topTreeStart, topTreeStop := v.vm.GetCompareIndexes()
-	result := "  "
-
-	if layerIdx >= bottomTreeStart && layerIdx <= bottomTreeStop {
-		result = format.CompareBottom("  ")
-	}
-	if layerIdx >= topTreeStart && layerIdx <= topTreeStop {
-		result = format.CompareTop("  ")
-	}
-
-	return result
-}
-
 func (v *Layer) ConstrainLayout() {
 	if !v.constrainedRealEstate {
 		logrus.Debugf("constraining layer layout")
@@ -293,7 +264,7 @@ func (v *Layer) Render() error {
 	logrus.Tracef("view.Render() %s", v.Name())
 
 	// indicate when selected
-	title := "Layers"
+	title := fmt.Sprintf("Layers (%d / %d)", v.vm.LayerIndex+1, len(v.vm.Layers))
 	isSelected := v.gui.CurrentView() == v.body
 
 	v.gui.Update(func(g *gocui.Gui) error {
@@ -319,28 +290,17 @@ func (v *Layer) Render() error {
 
 		// update contents
 		v.body.Clear()
-		for idx, layer := range v.vm.Layers {
-			var layerStr string
-			if v.constrainedRealEstate {
-				layerStr = fmt.Sprintf("%-4d", layer.Index)
-			} else {
-				layerStr = layer.String()
-			}
-
-			compareBar := v.renderCompareBar(idx)
-
-			if idx == v.vm.LayerIndex {
-				_, err = fmt.Fprintln(v.body, compareBar+" "+format.Selected(layerStr))
-			} else {
-				_, err = fmt.Fprintln(v.body, compareBar+" "+layerStr)
-			}
-
-			if err != nil {
-				logrus.Debug("unable to write to buffer: ", err)
-				return err
-			}
+		err = v.vm.Update(v.constrainedRealEstate)
+		if err != nil {
+			return err
 		}
-		return nil
+		err = v.vm.Render()
+		if err != nil {
+			return err
+		}
+		_, err = fmt.Fprint(v.body, v.vm.Buffer.String())
+
+		return err
 	})
 	return nil
 }

runtime/ui/view/layer_details.go

@@ -113,18 +113,12 @@ func (v *LayerDetails) IsVisible() bool {
 
 // CursorUp moves the cursor up in the details pane
 func (v *LayerDetails) CursorUp() error {
-	if err := CursorUp(v.gui, v.body); err != nil {
-		logrus.Debug("Couldn't move the cursor up")
-	}
-	return nil
+	return CursorUp(v.body, 1)
 }
 
 // CursorDown moves the cursor up in the details pane
 func (v *LayerDetails) CursorDown() error {
-	if err := CursorDown(v.gui, v.body); err != nil {
-		logrus.Debug("Couldn't move the cursor down")
-	}
-	return nil
+	return CursorDown(v.body, 1)
 }
 
 // KeyHelp indicates all the possible actions a user can take while the current pane is selected (currently does nothing).