a few miscellaneous fixes and improvements (#1105)

* add binding for more primitive backspace

* support selecting page up and page down

* fix matchbraceleft for braces that start on x=0

* fix multiline copy-paste indenting

let's say you have two lines like

  <space><space>line1
  <space><space>line2

so you start from cursor x=0 and select both lines, then paste.
we don't want any leading whitespace in this case, because the
cursor is already at x=0 and the selection already includes
whitespace.

cmd/micro/actions.go

@@ -1515,6 +1515,42 @@ func (v *View) PageDown(usePlugin bool) bool {
 	return false
 }
 
+// SelectPageUp selects up one page
+func (v *View) SelectPageUp(usePlugin bool) bool {
+	if usePlugin && !PreActionCall("SelectPageUp", v) {
+		return false
+	}
+
+	if !v.Cursor.HasSelection() {
+		v.Cursor.OrigSelection[0] = v.Cursor.Loc
+	}
+	v.Cursor.UpN(v.Height)
+	v.Cursor.SelectTo(v.Cursor.Loc)
+
+	if usePlugin {
+		return PostActionCall("SelectPageUp", v)
+	}
+	return true
+}
+
+// SelectPageDown selects down one page
+func (v *View) SelectPageDown(usePlugin bool) bool {
+	if usePlugin && !PreActionCall("SelectPageDown", v) {
+		return false
+	}
+
+	if !v.Cursor.HasSelection() {
+		v.Cursor.OrigSelection[0] = v.Cursor.Loc
+	}
+	v.Cursor.DownN(v.Height)
+	v.Cursor.SelectTo(v.Cursor.Loc)
+
+	if usePlugin {
+		return PostActionCall("SelectPageDown", v)
+	}
+	return true
+}
+
 // CursorPageUp places the cursor a page up
 func (v *View) CursorPageUp(usePlugin bool) bool {
 	if usePlugin && !PreActionCall("CursorPageUp", v) {

cmd/micro/bindings.go

@@ -80,6 +80,8 @@ var bindingActions = map[string]func(*View, bool) bool{
 	"End":                    (*View).End,
 	"PageUp":                 (*View).PageUp,
 	"PageDown":               (*View).PageDown,
+	"SelectPageUp":           (*View).SelectPageUp,
+	"SelectPageDown":         (*View).SelectPageDown,
 	"HalfPageUp":             (*View).HalfPageUp,
 	"HalfPageDown":           (*View).HalfPageDown,
 	"StartOfLine":            (*View).StartOfLine,
@@ -255,6 +257,7 @@ var bindingKeys = map[string]tcell.Key{
 	"Escape":         tcell.KeyEscape,
 	"Enter":          tcell.KeyEnter,
 	"Backspace":      tcell.KeyBackspace2,
+	"OldBackspace":   tcell.KeyBackspace,
 
 	// I renamed these keys to PageUp and PageDown but I don't want to break someone's keybindings
 	"PgUp":   tcell.KeyPgUp,

cmd/micro/cellview.go

@@ -76,8 +76,8 @@ func (c *CellView) Draw(buf *Buffer, top, height, left, width int) {
 			curX := buf.Cursor.X
 			curLoc := buf.Cursor.Loc
 			if buf.Settings["matchbraceleft"].(bool) {
-				curX--
 				if curX > 0 {
+					curX--
 					curLoc = curLoc.Move(-1, buf)
 				}
 			}

cmd/micro/view.go

@@ -198,7 +198,10 @@ func (v *View) ToggleTabbar() {
 }
 
 func (v *View) paste(clip string) {
-	leadingWS := GetLeadingWhitespace(v.Buf.Line(v.Cursor.Y))
+	leadingWS := ""
+	if v.Cursor.X > 0 {
+		leadingWS = GetLeadingWhitespace(v.Buf.Line(v.Cursor.Y))
+	}
 
 	if v.Cursor.HasSelection() {
 		v.Cursor.DeleteSelection()

runtime/help/keybindings.md

@@ -187,6 +187,8 @@ Start
 End
 PageUp
 PageDown
+SelectPageUp
+SelectPageDown
 HalfPageUp
 HalfPageDown
 StartOfLine
@@ -352,6 +354,7 @@ CtrlRightSq
 CtrlCarat
 CtrlUnderscore
 Backspace
+OldBackspace
 Tab
 Esc
 Escape