duit: add mouse chording cut/paste for Edit and Field

edit.go

@@ -114,6 +114,7 @@ type Edit struct {
 
 	textM,
 	prevTextB1 draw.Mouse
+	selecting bool
 
 	lastCursorPoint image.Point
 }
@@ -877,7 +878,10 @@ func (ui *Edit) Mouse(dui *DUI, self *Kid, m draw.Mouse, origM draw.Mouse, orig
 		ui.command = ""
 		ui.visual = ""
 	}
-	if m.Buttons == Button1 {
+	if om.Buttons&Button1 == 0 && m.Buttons&Button1 == 1 {
+		ui.selecting=true
+	}
+	if m.Buttons == Button1 && ui.selecting {
 		ui.cursor.Cur = mouseOffset()
 		ui.ScrollCursor(dui)
 		if om.Buttons == 0 {
@@ -899,10 +903,44 @@ func (ui *Edit) Mouse(dui *DUI, self *Kid, m draw.Mouse, origM draw.Mouse, orig
 	if m.Buttons^om.Buttons != 0 {
 		ui.text.closeHist(ui)
 		// log.Printf("in text, mouse buttons changed %v ->  %v\n", om, m)
+		if (om.Buttons&Button1 == 1 || m.Buttons&Button1 == 1) && om.Buttons&Button2 == 0 && m.Buttons&Button2 == Button2 {
+			sel, err := ui.Selection()
+			if err != nil {
+				log.Printf("duit: Selection: %s", err)
+				return
+			}
+			err = dui.Display.WriteSnarf([]byte(sel))
+			if err != nil {
+				log.Printf("duit: WriteSnarf: %s", err)
+				return
+			}
+			ui.Replace(ui.cursor, []byte(""))
+			s, e := ui.cursor.Start, ui.cursor.Cur
+			if s>e {
+				s,e = e,s
+			}
+			ui.cursor.Start=s
+			ui.cursor.Cur=s
+			ui.selecting = false
+			self.Draw = Dirty
+			ui.ScrollCursor(dui)
+		}
+		if (om.Buttons&Button1 == 1 || m.Buttons&Button1 == 1) && om.Buttons&Button3 == 0 && m.Buttons&Button3 == Button3 {
+			b, ok := dui.ReadSnarf()
+			if !ok {
+				// Just return, ReadSnarf doesn't return an error.
+				return
+			}
+			ui.Replace(ui.cursor, b)
+			ui.cursor.Cur = ui.cursor.Cur + int64(len(b))
+			self.Draw = Dirty
+			ui.ScrollCursor(dui)
+			ui.selecting = false
+		}
 	} else if m.Buttons != 0 && m.Buttons == om.Buttons {
-		// log.Printf("in text, mouse drag %v\n", m)
+		//log.Printf("in text, mouse drag %v\n", m)
 	} else if om.Buttons != 0 && m.Buttons == 0 {
-		// log.Printf("in text, button release %v -> %v\n", om, m)
+		//log.Printf("in text, button release %v -> %v\n", om, m)
 	}
 	r.Consumed = true
 	return

field.go

@@ -2,6 +2,7 @@ package duit
 
 import (
 	"image"
+	"log"
 	"strings"
 	"unicode/utf8"
 
@@ -301,6 +302,7 @@ func expandSelection(t string, i int) (s, e int) {
 }
 
 func (ui *Field) Mouse(dui *DUI, self *Kid, m draw.Mouse, origM draw.Mouse, orig image.Point) (r Result) {
+	defer func() { ui.m = m }()
 	if ui.Disabled {
 		return
 	}
@@ -330,21 +332,54 @@ func (ui *Field) Mouse(dui *DUI, self *Kid, m draw.Mouse, origM draw.Mouse, orig
 		ui.SelectionStart1 = ui.Cursor1
 		r.Consumed = true
 		self.Draw = Dirty
+		if m.Msec-ui.prevB1Release.Msec < 400 {
+			s, e := expandSelection(ui.Text, ui.cursor0())
+			ui.Cursor1 = 1 + s
+			ui.SelectionStart1 = 1 + e
+		}
 	} else if ui.m.Buttons&1 == 1 || m.Buttons&1 == 1 {
-		// continue selection
-		ui.Cursor1 = 1 + locateCursor()
 		r.Consumed = true
 		self.Draw = Dirty
-		if ui.m.Buttons&1 == 1 && m.Buttons&1 == 0 {
-			if m.Msec-ui.prevB1Release.Msec < 400 {
-				s, e := expandSelection(ui.Text, ui.cursor0())
-				ui.Cursor1 = 1 + s
-				ui.SelectionStart1 = 1 + e
+		if ui.m.Buttons&4 == 0 && m.Buttons&4 == 4 {
+			// b1 + b3 chord (Paste)
+			b, ok := dui.ReadSnarf()
+			if !ok {
+				// ReadSnarf does not return an error.
+				return
+			}
+			s, e, _ := ui.selection0()
+			if s != e {
+				ui.Text = ui.Text[:s] + string(b) + ui.Text[e:]
+				ui.Cursor1 = s + len(b) + 1
+			} else {
+				c := ui.cursor0()
+				ui.Text = ui.Text[:c] + string(b) + ui.Text[c:]
+				ui.Cursor1 = c + len(b) + 1
+			}
+			ui.SelectionStart1 = 0
+		} else if ui.m.Buttons&2 == 0 && m.Buttons&2 == 2 {
+			// b1 + b2 chord (Cut)
+			_, _, sel := ui.selection0()
+			err := dui.Display.WriteSnarf([]byte(sel))
+			if err != nil {
+				log.Printf("duit: writesnarf: %s\n", err)
+				return
+			}
+			ui.removeSelection()
+		} else if ui.SelectionStart1 > 0 {
+			// continue selection
+			ui.Cursor1 = 1 + locateCursor()
+			if ui.m.Buttons&1 == 1 && m.Buttons&1 == 0 {
+				if m.Msec-ui.prevB1Release.Msec < 400 {
+					s, e := expandSelection(ui.Text, ui.cursor0())
+					ui.Cursor1 = 1 + s
+					ui.SelectionStart1 = 1 + e
+				}
+				ui.prevB1Release = m
 			}
-			ui.prevB1Release = m
 		}
 	}
-	ui.m = m
+
 	return
 }