Labels may request an expanding height change

artist/text.go

@@ -17,6 +17,7 @@ type wordLayout struct {
 	position    image.Point
 	width       int
 	spaceAfter  int
+	breaksAfter int
 	text        []characterLayout
 }
 
@@ -167,13 +168,16 @@ func (drawer *TextDrawer) LineHeight () (height fixed.Int26_6) {
 func (drawer *TextDrawer) ReccomendedHeightFor (width int) (height int) {
 	if !drawer.layoutClean { drawer.recalculate() }
 	metrics := drawer.face.Metrics()
-	dot := fixed.Point26_6 { 0, 0 }
+	dot := fixed.Point26_6 { 0, metrics.Height }
 	for _, word := range drawer.layout {
-		dot.X += fixed.Int26_6((word.width + word.spaceAfter) << 6)
+		if word.width + dot.X.Round() > width {
-		
-		if word.width + word.position.X > width && word.position.X > 0 {
 			dot.Y += metrics.Height
-			dot.X = fixed.Int26_6(word.width << 6)
+			dot.X = 0
+		}
+		dot.X += fixed.I(word.width + word.spaceAfter)
+		if word.breaksAfter > 0 {
+			dot.Y += fixed.I(word.breaksAfter).Mul(metrics.Height)
+			dot.X = 0
 		}
 	}
 
@@ -246,6 +250,7 @@ func (drawer *TextDrawer) recalculate () {
 			if character == '\n' {
 				dot.Y += metrics.Height
 				dot.X = 0
+				word.breaksAfter ++
 				previousCharacter = character
 				index ++
 			} else {
@@ -290,7 +295,6 @@ func (drawer *TextDrawer) recalculate () {
 
 	if drawer.wrap {
 		drawer.layoutBounds.Max.X = drawer.width
-		println("aaa")
 	} else {
 		drawer.layoutBounds.Max.X = horizontalExtent
 	}

backends/x/window.go

@@ -89,6 +89,7 @@ func (window *Window) Adopt (child tomo.Element) {
 		child.SetParentHooks (tomo.ParentHooks {
 			Draw: window.childDrawCallback,
 			MinimumSizeChange: window.childMinimumSizeChangeCallback,
+			ExpandingHeightChange: window.resizeChildToFit,
 			SelectionRequest: window.childSelectionRequestCallback,
 		})
 		
@@ -205,8 +206,25 @@ func (window *Window) resizeChildToFit () {
 	if child, ok := window.child.(tomo.Expanding); ok {
 		minimumHeight := child.MinimumHeightFor(window.metrics.width)
 		_, minimumWidth := child.MinimumSize()
-		window.childMinimumSizeChangeCallback (
+		
-			minimumWidth, minimumHeight)
+			
+		icccm.WmNormalHintsSet (
+			window.backend.connection,
+			window.xWindow.Id,
+			&icccm.NormalHints {
+				Flags:     icccm.SizeHintPMinSize,
+				MinWidth:  uint(minimumWidth),
+				MinHeight: uint(minimumHeight),
+			})
+				
+		if window.metrics.height >= minimumHeight &&
+			window.metrics.width >= minimumWidth {
+			
+			window.child.Resize (
+				window.metrics.width,
+				window.metrics.height)
+				window.redrawChildEntirely()
+		}
 	} else {
 		window.child.Resize (
 			window.metrics.width,

element.go

@@ -16,6 +16,10 @@ type ParentHooks struct {
 	// event.
 	MinimumSizeChange func (width, height int)
 
+	// ExpandingHeightChange is called when the parameters affecting the
+	// element's expanding height have changed.
+	ExpandingHeightChange func ()
+	
 	// SelectionRequest is called when the child element element wants
 	// itself to be selected. If the parent element chooses to grant the
 	// request, it must send the child element a selection event and return
@@ -42,6 +46,14 @@ func (hooks ParentHooks) RunMinimumSizeChange (width, height int) {
 	}
 }
 
+// RunExpandingHeightChange runs the ExpandingHeightChange hook if it is not
+// nil. If it is nil, it does nothing.
+func (hooks ParentHooks) RunExpandingHeightChange () {
+	if hooks.ExpandingHeightChange != nil {
+		hooks.ExpandingHeightChange()
+	}
+}
+
 // RunSelectionRequest runs the SelectionRequest hook if it is not nil. If it is
 // nil, it does nothing.
 func (hooks ParentHooks) RunSelectionRequest () (granted bool) {

elements/basic/label.go

@@ -27,6 +27,7 @@ func NewLabel (text string, wrap bool) (element *Label) {
 	return
 }
 
+// Resize resizes the label and re-wraps the text if wrapping is enabled.
 func (element *Label) Resize (width, height int) {
 	element.core.AllocateCanvas(width, height)
 	if element.wrap {
@@ -37,6 +38,17 @@ func (element *Label) Resize (width, height int) {
 	return
 }
 
+// MinimumHeightFor returns the reccomended height for this element based on the
+// given width in order to allow the text to wrap properly.
+func (element *Label) MinimumHeightFor (width int) (height int) {
+	if element.wrap {
+		return element.drawer.ReccomendedHeightFor(width)
+	} else {
+		_, height = element.MinimumSize()
+		return
+	}
+}
+
 // SetText sets the label's text.
 func (element *Label) SetText (text string) {
 	if element.text == text { return }
@@ -76,6 +88,7 @@ func (element *Label) updateMinimumSize () {
 		if em < 1 { em = theme.Padding() }
 		element.core.SetMinimumSize (
 			em, element.drawer.LineHeight().Round())
+		element.core.NotifyExpandingHeightChange()
 	} else {
 		bounds := element.drawer.LayoutBounds()
 		element.core.SetMinimumSize(bounds.Dx(), bounds.Dy())

elements/core/core.go

@@ -144,6 +144,12 @@ func (control CoreControl) SetMinimumSize (width, height int) {
 	}
 }
 
+// NotifyExpandingHeightChange notifies the parent element that this element's
+// expanding height has changed.
+func (control CoreControl) NotifyExpandingHeightChange () {
+	control.core.hooks.RunExpandingHeightChange()
+}
+
 // ConstrainSize contstrains the specified width and height to the minimum width
 // and height, and returns wether or not anything ended up being constrained.
 func (control CoreControl) ConstrainSize (

examples/flow/main.go

@@ -21,7 +21,7 @@ func run () {
 	world.Stages = map [string] func () {
 		"start": func () {
 			label := basic.NewLabel (
-				"you are standing next to a river.", false)
+				"you are standing next to a river.", true)
 			
 			button0 := basic.NewButton("go in the river")
 			button0.OnClick(world.SwitchFunc("wet"))
@@ -41,7 +41,7 @@ func run () {
 		"wet": func () {
 			label := basic.NewLabel (
 				"you get completely soaked.\n" +
-				"you die of hypothermia.", false)
+				"you die of hypothermia.", true)
 			
 			button0 := basic.NewButton("try again")
 			button0.OnClick(world.SwitchFunc("start"))
@@ -58,7 +58,7 @@ func run () {
 		"house": func () {
 			label := basic.NewLabel (
 				"you are standing in front of a delapidated " +
-				"house.", false)
+				"house.", true)
 			
 			button1 := basic.NewButton("go inside")
 			button1.OnClick(world.SwitchFunc("inside"))
@@ -78,7 +78,7 @@ func run () {
 				"it is dark, but rays of light stream " +
 				"through the window.\n" +
 				"there is nothing particularly interesting " +
-				"here.", false)
+				"here.", true)
 			
 			button0 := basic.NewButton("go back outside")
 			button0.OnClick(world.SwitchFunc("house"))
@@ -92,7 +92,7 @@ func run () {
 		"bear": func () {
 			label := basic.NewLabel (
 				"you come face to face with a bear.\n" +
-				"it eats you (it was hungry).", false)
+				"it eats you (it was hungry).", true)
 			
 			button0 := basic.NewButton("try again")
 			button0.OnClick(world.SwitchFunc("start"))

examples/label/main.go

@@ -9,7 +9,7 @@ func main () {
 }
 
 func run () {
-	window, _ := tomo.NewWindow(480, 360)
+	window, _ := tomo.NewWindow(480, 2)
 	window.SetTitle("example label")
 	window.Adopt(basic.NewLabel(text, true))
 	window.OnClose(tomo.Stop)