Overhauled mouse events

Everything gets an image.Point instead of an x y pair, and most
things now get modifiers.

backends/x/event.go

@@ -189,6 +189,7 @@ func (window *window) handleButtonPress (
 	point        := image.Pt(int(buttonEvent.EventX), int(buttonEvent.EventY))
 	insideWindow := point.In(window.canvas.Bounds())
 	scrolling    := buttonEvent.Detail >= 4 && buttonEvent.Detail <= 7
+	modifiers    := window.modifiersFromState(buttonEvent.State)
 
 	if !insideWindow && window.shy && !scrolling {
 		window.Close()
@@ -200,8 +201,8 @@ func (window *window) handleButtonPress (
 				sum.add(buttonEvent.Detail, window, buttonEvent.State)
 				window.compressScrollSum(buttonEvent, &sum)
 				child.HandleScroll (
-					point.X, point.Y,
+					point, float64(sum.x), float64(sum.y),
-					float64(sum.x), float64(sum.y))
+					modifiers)
 			}
 		}
 	} else {
@@ -209,14 +210,13 @@ func (window *window) handleButtonPress (
 		window.system.drags[buttonEvent.Detail] = underneath
 		if child, ok := underneath.element.(tomo.MouseTarget); ok {
 			child.HandleMouseDown (
-				point.X, point.Y,
+				point, input.Button(buttonEvent.Detail),
-				input.Button(buttonEvent.Detail))
+				modifiers)
 		}
 		callback := func (container tomo.MouseTargetContainer, child tomo.Element) {
 			container.HandleChildMouseDown (
-				point.X, point.Y,
+				point, input.Button(buttonEvent.Detail),
-				input.Button(buttonEvent.Detail),
+				modifiers, child)
-				child)
 		}
 		underneath.forMouseTargetContainers(callback)
 	}
@@ -230,20 +230,25 @@ func (window *window) handleButtonRelease (
 ) {
 	buttonEvent := *event.ButtonReleaseEvent
 	if buttonEvent.Detail >= 4 && buttonEvent.Detail <= 7 { return }
+	modifiers := window.modifiersFromState(buttonEvent.State)
 	dragging := window.system.drags[buttonEvent.Detail]
+	
 	if dragging != nil {
 		if child, ok := dragging.element.(tomo.MouseTarget); ok {
 			child.HandleMouseUp (
-				int(buttonEvent.EventX),
+				image.Pt (
-				int(buttonEvent.EventY),
+					int(buttonEvent.EventX),
-				input.Button(buttonEvent.Detail))
+					int(buttonEvent.EventY)),
+				input.Button(buttonEvent.Detail),
+				modifiers)
 		}
 		callback := func (container tomo.MouseTargetContainer, child tomo.Element) {
 			container.HandleChildMouseUp (
-			int(buttonEvent.EventX),
+				image.Pt (
-			int(buttonEvent.EventY),
+					int(buttonEvent.EventX),
-			input.Button(buttonEvent.Detail),
+					int(buttonEvent.EventY)),
-			child)
+				input.Button(buttonEvent.Detail),
+				modifiers, child)
 		}
 		dragging.forMouseTargetContainers(callback)
 	}
@@ -263,7 +268,7 @@ func (window *window) handleMotionNotify (
 	for _, child := range window.system.drags {
 		if child == nil { continue }
 		if child, ok := child.element.(tomo.MotionTarget); ok {
-			child.HandleMotion(x, y)
+			child.HandleMotion(image.Pt(x, y))
 			handled = true
 		}
 	}
@@ -271,7 +276,7 @@ func (window *window) handleMotionNotify (
 	if !handled {
 		child := window.system.childAt(image.Pt(x, y))
 		if child, ok := child.element.(tomo.MotionTarget); ok {
-			child.HandleMotion(x, y)
+			child.HandleMotion(image.Pt(x, y))
 		}
 	}
 	

element.go

@@ -99,11 +99,17 @@ type MouseTarget interface {
 
 	// HandleMouseDown is called when a mouse button is pressed down on this
 	// element.
-	HandleMouseDown (x, y int, button input.Button)
+	HandleMouseDown (
+		position image.Point,
+		button input.Button,
+		modifiers input.Modifiers)
 
 	// HandleMouseUp is called when a mouse button is released that was
 	// originally pressed down on this element.
-	HandleMouseUp (x, y int, button input.Button)
+	HandleMouseUp (
+		position image.Point,
+		button input.Button,
+		modifiers input.Modifiers)
 }
 
 // MouseTargetContainer represents an element that wants to know when one
@@ -115,11 +121,19 @@ type MouseTargetContainer interface {
 
 	// HandleMouseDown is called when a mouse button is pressed down on a
 	// child element.
-	HandleChildMouseDown (x, y int, button input.Button, child Element)
+	HandleChildMouseDown (
+		position image.Point,
+		button input.Button,
+		modifiers input.Modifiers,
+		child Element)
 
 	// HandleMouseUp is called when a mouse button is released that was
 	// originally pressed down on a child element.
-	HandleChildMouseUp (x, y int, button input.Button, child Element)
+	HandleChildMouseUp (
+		position image.Point,
+		button input.Button,
+		modifiers input.Modifiers,
+		child Element)
 }
 
 // MotionTarget represents an element that can receive mouse motion events.
@@ -129,7 +143,7 @@ type MotionTarget interface {
 	// HandleMotion is called when the mouse is moved over this element,
 	// or the mouse is moving while being held down and originally pressed
 	// down on this element.
-	HandleMotion (x, y int)
+	HandleMotion (position image.Point)
 }
 
 // ScrollTarget represents an element that can receive mouse scroll events.
@@ -138,7 +152,10 @@ type ScrollTarget interface {
 
 	// HandleScroll is called when the mouse is scrolled. The X and Y
 	// direction of the scroll event are passed as deltaX and deltaY.
-	HandleScroll (x, y int, deltaX, deltaY float64)
+	HandleScroll (
+		position image.Point,
+		deltaX, deltaY float64,
+		modifiers input.Modifiers)
 }
 
 // Flexible represents an element who's preferred minimum height can change in
@@ -158,7 +175,8 @@ type Flexible interface {
 	// minimum size that the element may be resized to.
 	//
 	// It is important to note that if a parent container checks for
-	// flexible chilren, it itself will likely need to be flexible.
+	// flexible chilren, it itself will likely need to be either scrollable
+	// or flexible.
 	FlexibleHeightFor (width int) int
 }
 

elements/button.go

@@ -177,7 +177,11 @@ func (element *Button) HandleFocusChange () {
 	element.entity.Invalidate()
 }
 
-func (element *Button) HandleMouseDown (x, y int, button input.Button) {
+func (element *Button) HandleMouseDown (
+	position image.Point,
+	button input.Button,
+	modifiers input.Modifiers,
+) {
 	if !element.Enabled() { return }
 	element.Focus()
 	if button != input.ButtonLeft { return }
@@ -185,10 +189,14 @@ func (element *Button) HandleMouseDown (x, y int, button input.Button) {
 	element.entity.Invalidate()
 }
 
-func (element *Button) HandleMouseUp (x, y int, button input.Button) {
+func (element *Button) HandleMouseUp (
+	position image.Point,
+	button input.Button,
+	modifiers input.Modifiers,
+) {
 	if button != input.ButtonLeft { return }
 	element.pressed = false
-	within := image.Point { x, y }.In(element.entity.Bounds())
+	within := position.In(element.entity.Bounds())
 	if element.Enabled() && within && element.onClick != nil {
 		element.onClick()
 	}

elements/checkbox.go

@@ -130,18 +130,26 @@ func (element *Checkbox) HandleFocusChange () {
 	element.entity.Invalidate()
 }
 
-func (element *Checkbox) HandleMouseDown (x, y int, button input.Button) {
+func (element *Checkbox) HandleMouseDown (
+	position image.Point,
+	button input.Button,
+	modifiers input.Modifiers,
+) {
 	if !element.Enabled() { return }
 	element.Focus()
 	element.pressed = true
 	element.entity.Invalidate()
 }
 
-func (element *Checkbox) HandleMouseUp (x, y int, button input.Button) {
+func (element *Checkbox) HandleMouseUp (
+	position image.Point,
+	button input.Button,
+	modifiers input.Modifiers,
+) {
 	if button != input.ButtonLeft || !element.pressed { return }
 
 	element.pressed = false
-	within := image.Point { x, y }.In(element.entity.Bounds())
+	within := position.In(element.entity.Bounds())
 	if within {
 		element.checked = !element.checked
 	}

elements/directory.go

@@ -124,13 +124,26 @@ func (element *Directory) Layout () {
 	}
 }
 
-func (element *Directory) HandleMouseDown (x, y int, button input.Button) {
+func (element *Directory) HandleMouseDown  (
+	position image.Point,
+	button input.Button,
+	modifiers input.Modifiers,
+) {
 	element.selectNone()
 }
 
-func (element *Directory) HandleMouseUp (x, y int, button input.Button) { }
+func (element *Directory) HandleMouseUp  (
+	position image.Point,
+	button input.Button,
+	modifiers input.Modifiers,
+) { }
 
-func (element *Directory) HandleChildMouseDown (x, y int, button input.Button, child tomo.Element) {
+func (element *Directory) HandleChildMouseDown  (
+	position image.Point,
+	button input.Button,
+	modifiers input.Modifiers,
+	child tomo.Element,
+) {
 	element.selectNone()
 	if child, ok := child.(tomo.Selectable); ok {
 		index := element.entity.IndexOf(child)
@@ -138,7 +151,12 @@ func (element *Directory) HandleChildMouseDown (x, y int, button input.Button, c
 	}
 }
 
-func (element *Directory) HandleChildMouseUp (int, int, input.Button, tomo.Element) { }
+func (element *Directory) HandleChildMouseUp  (
+	position image.Point,
+	button input.Button,
+	modifiers input.Modifiers,
+	child tomo.Element,
+) { }
 
 func (element *Directory) HandleChildFlexibleHeightChange (child tomo.Flexible) {
 	element.updateMinimumSize()

elements/file.go

@@ -125,7 +125,7 @@ func (element *File) HandleKeyDown (key input.Key, modifiers input.Modifiers) {
 	}
 }
 
-func (element *File) HandleKeyUp(key input.Key, modifiers input.Modifiers) {
+func (element *File) HandleKeyUp (key input.Key, modifiers input.Modifiers) {
 	if key == input.KeyEnter && element.pressed {
 		element.pressed = false
 		if !element.Enabled() { return }
@@ -165,7 +165,11 @@ func (element *File) SetEnabled (enabled bool) {
 	element.entity.Invalidate()
 }
 
-func (element *File) HandleMouseDown (x, y int, button input.Button) {
+func (element *File) HandleMouseDown  (
+	position image.Point,
+	button input.Button,
+	modifiers input.Modifiers,
+) {
 	if !element.Enabled() { return }
 	if !element.entity.Focused() { element.Focus() }
 	if button != input.ButtonLeft { return }
@@ -173,10 +177,14 @@ func (element *File) HandleMouseDown (x, y int, button input.Button) {
 	element.entity.Invalidate()
 }
 
-func (element *File) HandleMouseUp (x, y int, button input.Button) {
+func (element *File) HandleMouseUp  (
+	position image.Point,
+	button input.Button,
+	modifiers input.Modifiers,
+) {
 	if button != input.ButtonLeft { return }
 	element.pressed = false
-	within := image.Point { x, y }.In(element.entity.Bounds())
+	within := position.In(element.entity.Bounds())
 	if time.Since(element.lastClick) < element.config.DoubleClickDelay() {
 		if element.Enabled() && within && element.onChoose != nil {
 			element.onChoose()

elements/list.go

@@ -87,7 +87,12 @@ func (element *List) Layout () {
 	}
 }
 
-func (element *List) HandleChildMouseDown (x, y int, button input.Button, child tomo.Element) {
+func (element *List) HandleChildMouseDown  (
+	position image.Point,
+	button input.Button,
+	modifiers input.Modifiers,
+	child tomo.Element,
+) {
 	if child, ok := child.(tomo.Selectable); ok {
 		index := element.entity.IndexOf(child)
 		if element.selected == index { return }
@@ -99,7 +104,12 @@ func (element *List) HandleChildMouseDown (x, y int, button input.Button, child
 	}
 }
 
-func (element *List) HandleChildMouseUp (int, int, input.Button, tomo.Element) { }
+func (element *List) HandleChildMouseUp  (
+	position image.Point,
+	button input.Button,
+	modifiers input.Modifiers,
+	child tomo.Element,
+) { }
 
 func (element *List) HandleChildFlexibleHeightChange (child tomo.Flexible) {
 	element.updateMinimumSize()

elements/scroll.go

@@ -2,7 +2,7 @@ package elements
 
 import "image"
 import "git.tebibyte.media/sashakoshka/tomo"
-// import "git.tebibyte.media/sashakoshka/tomo/input"
+import "git.tebibyte.media/sashakoshka/tomo/input"
 import "git.tebibyte.media/sashakoshka/tomo/canvas"
 import "git.tebibyte.media/sashakoshka/tomo/default/theme"
 import "git.tebibyte.media/sashakoshka/tomo/default/config"
@@ -179,8 +179,9 @@ func (element *Scroll) HandleChildScrollBoundsChange (tomo.Scrollable) {
 }
 
 func (element *Scroll) HandleScroll (
-	x, y int,
+	position image.Point,
 	deltaX, deltaY float64,
+	modifiers input.Modifiers,
 ) {
 	horizontal, vertical := element.child.ScrollAxes()
 	if !horizontal { deltaX = 0 }

elements/scrollbar.go

@@ -82,18 +82,21 @@ func (element *ScrollBar) Draw (destination canvas.Canvas) {
 		element.bar)
 }
 
-func (element *ScrollBar) HandleMouseDown (x, y int, button input.Button) {
+func (element *ScrollBar) HandleMouseDown  (
+	position image.Point,
+	button input.Button,
+	modifiers input.Modifiers,
+) {
 	velocity := element.config.ScrollVelocity()
-	point := image.Pt(x, y)
 
-	if point.In(element.bar) {
+	if position.In(element.bar) {
 		// the mouse is pressed down within the bar's handle
 		element.dragging   = true
 		element.entity.Invalidate()
 		element.dragOffset =
-			point.Sub(element.bar.Min).
+			position.Sub(element.bar.Min).
 			Add(element.entity.Bounds().Min)
-		element.dragTo(point)
+		element.dragTo(position)
 	} else {
 		// the mouse is pressed down within the bar's gutter
 		switch button {
@@ -102,7 +105,7 @@ func (element *ScrollBar) HandleMouseDown (x, y int, button input.Button) {
 			// the middle of the handle
 			element.dragging = true
 			element.dragOffset = element.fallbackDragOffset()
-			element.dragTo(point)
+			element.dragTo(position)
 			
 		case input.ButtonMiddle:
 			// page up/down on middle click
@@ -112,7 +115,7 @@ func (element *ScrollBar) HandleMouseDown (x, y int, button input.Button) {
 			} else {
 				viewport = element.viewportBounds.Dx()
 			}
-			if element.isAfterHandle(point) {
+			if element.isAfterHandle(position) {
 				element.scrollBy(viewport)
 			} else {
 				element.scrollBy(-viewport)
@@ -120,7 +123,7 @@ func (element *ScrollBar) HandleMouseDown (x, y int, button input.Button) {
 			
 		case input.ButtonRight:
 			// inch up/down on right click
-			if element.isAfterHandle(point) {
+			if element.isAfterHandle(position) {
 				element.scrollBy(velocity)
 			} else {
 				element.scrollBy(-velocity)
@@ -129,20 +132,28 @@ func (element *ScrollBar) HandleMouseDown (x, y int, button input.Button) {
 	}
 }
 
-func (element *ScrollBar) HandleMouseUp (x, y int, button input.Button) {
+func (element *ScrollBar) HandleMouseUp  (
+	position image.Point,
+	button input.Button,
+	modifiers input.Modifiers,
+) {
 	if element.dragging {
 		element.dragging = false
 		element.entity.Invalidate()
 	}
 }
 
-func (element *ScrollBar) HandleMotion (x, y int) {
+func (element *ScrollBar) HandleMotion (position image.Point) {
 	if element.dragging {
-		element.dragTo(image.Pt(x, y))
+		element.dragTo(position)
 	}
 }
 
-func (element *ScrollBar) HandleScroll (x, y int, deltaX, deltaY float64) {
+func (element *ScrollBar) HandleScroll (
+	position image.Point,
+	deltaX, deltaY float64,
+	modifiers input.Modifiers,
+) {
 	if element.vertical {
 		element.scrollBy(int(deltaY))
 	} else {

elements/slider.go

@@ -111,12 +111,16 @@ func (element *slider) HandleFocusChange () {
 	element.entity.Invalidate()
 }
 
-func (element *slider) HandleMouseDown (x, y int, button input.Button) {
+func (element *slider) HandleMouseDown  (
+	position image.Point,
+	button input.Button,
+	modifiers input.Modifiers,
+) {
 	if !element.Enabled() { return }
 	element.Focus()
 	if button == input.ButtonLeft {
 		element.dragging = true
-		element.value = element.valueFor(x, y)
+		element.value = element.valueFor(position.X, position.Y)
 		if element.onSlide != nil {
 			element.onSlide()
 		}
@@ -124,7 +128,11 @@ func (element *slider) HandleMouseDown (x, y int, button input.Button) {
 	}
 }
 
-func (element *slider) HandleMouseUp (x, y int, button input.Button) {
+func (element *slider) HandleMouseUp  (
+	position image.Point,
+	button input.Button,
+	modifiers input.Modifiers,
+) {
 	if button != input.ButtonLeft || !element.dragging { return }
 	element.dragging = false
 	if element.onRelease != nil {
@@ -133,10 +141,10 @@ func (element *slider) HandleMouseUp (x, y int, button input.Button) {
 	element.entity.Invalidate()
 }
 
-func (element *slider) HandleMotion (x, y int) {
+func (element *slider) HandleMotion (position image.Point) {
 	if element.dragging {
 		element.dragging = true
-		element.value = element.valueFor(x, y)
+		element.value = element.valueFor(position.X, position.Y)
 		if element.onSlide != nil {
 			element.onSlide()
 		}
@@ -144,7 +152,11 @@ func (element *slider) HandleMotion (x, y int) {
 	}
 }
 
-func (element *slider) HandleScroll (x, y int, deltaX, deltaY float64) { }
+func (element *slider) HandleScroll (
+	position image.Point,
+	deltaX, deltaY float64,
+	modifiers input.Modifiers,
+) { }
 
 func (element *slider) HandleKeyDown (key input.Key, modifiers input.Modifiers) {
 	switch key {

elements/switch.go

@@ -101,19 +101,26 @@ func (element *Switch) HandleFocusChange () {
 	element.entity.Invalidate()
 }
 
-func (element *Switch) HandleMouseDown (x, y int, button input.Button) {
+func (element *Switch) HandleMouseDown  (
+	position image.Point,
+	button input.Button,
+	modifiers input.Modifiers,
+) {
 	if !element.Enabled() { return }
 	element.Focus()
 	element.pressed = true
 	element.entity.Invalidate()
 }
 
-func (element *Switch) HandleMouseUp (x, y int, button input.Button) {
+func (element *Switch) HandleMouseUp (
+	position image.Point,
+	button input.Button,
+	modifiers input.Modifiers,
+) {
 	if button != input.ButtonLeft || !element.pressed { return }
 
 	element.pressed = false
-	within := image.Point { x, y }.
+	within := position.In(element.entity.Bounds())
-		In(element.entity.Bounds())
 	if within {
 		element.checked = !element.checked
 	}

elements/textbox.go

@@ -143,12 +143,16 @@ func (element *TextBox) HandleFocusChange () {
 	element.entity.Invalidate()
 }
 
-func (element *TextBox) HandleMouseDown (x, y int, button input.Button) {
+func (element *TextBox) HandleMouseDown  (
+	position image.Point,
+	button input.Button,
+	modifiers input.Modifiers,
+) {
 	if !element.Enabled() { return }
 	element.Focus()
 
 	if button == input.ButtonLeft {
-		runeIndex := element.atPosition(image.Pt(x, y))
+		runeIndex := element.atPosition(position)
 		if runeIndex == -1 { return }
 		
 		if time.Since(element.lastClick) < element.config.DoubleClickDelay() {
@@ -164,19 +168,19 @@ func (element *TextBox) HandleMouseDown (x, y int, button input.Button) {
 	}
 }
 
-func (element *TextBox) HandleMotion (x, y int) {
+func (element *TextBox) HandleMotion (position image.Point) {
 	if !element.Enabled() { return }
 
 	switch element.dragging {
 	case 1:
-		runeIndex := element.atPosition(image.Pt(x, y))
+		runeIndex := element.atPosition(position)
 		if runeIndex > -1 {
 			element.dot.End = runeIndex
 			element.entity.Invalidate()
 		}
 		
 	case 2:
-		runeIndex := element.atPosition(image.Pt(x, y))
+		runeIndex := element.atPosition(position)
 		if runeIndex > -1 {
 			if runeIndex < element.dot.Start {
 				element.dot.End =
@@ -213,7 +217,11 @@ func (element *TextBox) atPosition (position image.Point) int {
 		fixedutil.Pt(position.Sub(offset).Add(textBoundsMin)))
 }
 
-func (element *TextBox) HandleMouseUp (x, y int, button input.Button) {
+func (element *TextBox) HandleMouseUp  (
+	position image.Point,
+	button input.Button,
+	modifiers input.Modifiers,
+) {
 	if button == input.ButtonLeft {
 		element.dragging = 0
 	}