Add word selection with double click

src/cursor.go

@@ -42,7 +42,11 @@ type Cursor struct {
 	x int
 	y int
 
-	curSelection  [2]int
+	// The current selection as a range of character numbers (inclusive)
+	curSelection [2]int
+	// The original selection as a range of character numbers
+	// This is used for line and word selection where it is necessary
+	// to know what the original selection was
 	origSelection [2]int
 }
 
@@ -97,43 +101,93 @@ func (c *Cursor) SelectLine() {
 	c.End()
 	c.curSelection[1] = c.Loc()
 
-	c.origSelection[0] = c.curSelection[0]
+	c.origSelection = c.curSelection
-	c.origSelection[1] = c.curSelection[1]
 }
 
 // AddLineToSelection adds the current line to the selection
 func (c *Cursor) AddLineToSelection() {
 	loc := c.Loc()
 
+	if loc < c.origSelection[0] {
+		c.Start()
+		c.curSelection[0] = c.Loc()
+		c.curSelection[1] = c.origSelection[1]
+	}
+	if loc > c.origSelection[1] {
+		c.End()
+		c.curSelection[1] = c.Loc()
+		c.curSelection[0] = c.origSelection[0]
+	}
+
+	if loc < c.origSelection[1] && loc > c.origSelection[0] {
+		c.curSelection = c.origSelection
+	}
+}
+
+// SelectWord selects the word the cursor is currently on
+func (c *Cursor) SelectWord() {
+	if !IsWordChar(string(c.RuneUnder(c.x))) {
+		return
+	}
+
+	forward, backward := c.x, c.x
+
+	for backward > 0 && IsWordChar(string(c.RuneUnder(backward-1))) {
+		backward--
+	}
+
+	c.curSelection[0] = ToCharPos(backward, c.y, c.v.buf)
+	c.origSelection[0] = c.curSelection[0]
+
+	for forward < Count(c.v.buf.lines[c.y])-1 && IsWordChar(string(c.RuneUnder(forward+1))) {
+		forward++
+	}
+
+	c.curSelection[1] = ToCharPos(forward, c.y, c.v.buf)
+	c.origSelection[1] = c.curSelection[1]
+}
+
+// AddWordToSelection adds the word the cursor is currently on to the selection
+func (c *Cursor) AddWordToSelection() {
+	loc := c.Loc()
+
 	if loc > c.origSelection[0] && loc < c.origSelection[1] {
 		c.curSelection = c.origSelection
 		return
 	}
 
 	if loc < c.origSelection[0] {
-		c.Start()
+		backward := c.x
-		c.curSelection[0] = c.Loc()
+
-	} else if loc > c.origSelection[1] {
+		for backward > 0 && IsWordChar(string(c.RuneUnder(backward-1))) {
-		c.End()
+			backward--
-		c.curSelection[1] = c.Loc()
+		}
+
+		c.curSelection[0] = ToCharPos(backward, c.y, c.v.buf)
+		c.curSelection[1] = c.origSelection[1]
 	}
 
-	if loc < c.curSelection[0] {
+	if loc > c.origSelection[1] {
-		c.Start()
+		forward := c.x
-		c.curSelection[0] = c.Loc()
+
-	} else if loc > c.curSelection[1] {
+		for forward < Count(c.v.buf.lines[c.y])-1 && IsWordChar(string(c.RuneUnder(forward+1))) {
-		c.End()
+			forward++
-		c.curSelection[1] = c.Loc()
+		}
+
+		c.curSelection[1] = ToCharPos(forward, c.y, c.v.buf)
+		c.curSelection[0] = c.origSelection[0]
 	}
 }
 
-// RuneUnder returns the rune under the cursor
+// RuneUnder returns the rune under the given x position
-func (c *Cursor) RuneUnder() rune {
+func (c *Cursor) RuneUnder(x int) rune {
-	line := c.v.buf.lines[c.y]
+	line := []rune(c.v.buf.lines[c.y])
-	if c.x >= Count(line) {
+	if x >= len(line) {
-		return ' '
+		x = len(line) - 1
+	} else if x < 0 {
+		x = 0
 	}
-	return []rune(line)[c.x]
+	return line[x]
 }
 
 // Up moves the cursor up one line (if possible)

src/util.go

@@ -48,3 +48,15 @@ func Max(a, b int) int {
 	}
 	return b
 }
+
+// IsWordChar returns whether or not the string is a 'word character'
+// If it is a unicode character, then it does not match
+// Word characters are defined as [A-Za-z0-9_]
+func IsWordChar(str string) bool {
+	if len(str) > 1 {
+		// Unicode
+		return false
+	}
+	c := str[0]
+	return (c >= '0' && c <= '9') || (c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z') || (c == '_')
+}

src/util_test.go

@@ -33,3 +33,33 @@ func TestSpaces(t *testing.T) {
 		}
 	}
 }
+
+func TestIsWordChar(t *testing.T) {
+	if IsWordChar("t") == false {
+		t.Errorf("IsWordChar(t) = false")
+	}
+	if IsWordChar("T") == false {
+		t.Errorf("IsWordChar(T) = false")
+	}
+	if IsWordChar("5") == false {
+		t.Errorf("IsWordChar(5) = false")
+	}
+	if IsWordChar("_") == false {
+		t.Errorf("IsWordChar(_) = false")
+	}
+	if IsWordChar("~") == true {
+		t.Errorf("IsWordChar(~) = true")
+	}
+	if IsWordChar(" ") == true {
+		t.Errorf("IsWordChar( ) = true")
+	}
+	if IsWordChar("ß") == true {
+		t.Errorf("IsWordChar(ß) = true")
+	}
+	if IsWordChar(")") == true {
+		t.Errorf("IsWordChar()) = true")
+	}
+	if IsWordChar("\n") == true {
+		t.Errorf("IsWordChar(\n)) = true")
+	}
+}

src/view.go

@@ -456,14 +456,19 @@ func (v *View) HandleEvent(event tcell.Event) {
 					if v.doubleClick {
 						// Triple click
 						v.lastClickTime = time.Now()
+
 						v.tripleClick = true
 						v.doubleClick = false
+
 						v.cursor.SelectLine()
 					} else {
 						// Double click
+						v.lastClickTime = time.Now()
+
 						v.doubleClick = true
 						v.tripleClick = false
-						v.lastClickTime = time.Now()
+
+						v.cursor.SelectWord()
 					}
 				} else {
 					v.doubleClick = false
@@ -478,7 +483,7 @@ func (v *View) HandleEvent(event tcell.Event) {
 				if v.tripleClick {
 					v.cursor.AddLineToSelection()
 				} else if v.doubleClick {
-
+					v.cursor.AddWordToSelection()
 				} else {
 					v.cursor.curSelection[1] = v.cursor.Loc()
 				}

todolist.md

@@ -8,10 +8,6 @@
 
 - [ ] Search and replace
 
-- [ ] Better selection
-    - [ ] Double click selects current word
-    - [x] Triple click enables line selection
-
 - [ ] More keybindings
     - [x] Page up and page down
     - [x] CtrlA for select all
@@ -40,6 +36,10 @@
     - [x] Help screen which lists keybindings and commands
     - [x] Opened with Ctrl-h
 
+- [x] Better selection
+    - [x] Double click selects current word
+    - [x] Triple click enables line selection
+
 - [x] Options
     - [x] Colorscheme
     - [x] tab size