Document works now

elements/containers/box.go

@@ -8,7 +8,8 @@ import "git.tebibyte.media/sashakoshka/tomo/default/theme"
 
 type scratchEntry struct {
 	expand     bool
-	minimum float64
+	minSize    float64
+	minBreadth float64
 }
 
 // Box is a container that lays out its children horizontally or vertically.
@@ -80,7 +81,7 @@ func (element *Box) Layout () {
 		var size float64; if entry.expand {
 			size = expandingElementSize
 		} else {
-			size = entry.minimum
+			size = entry.minSize
 		}
 
 		var childBounds image.Rectangle; if element.vertical {
@@ -170,7 +171,7 @@ func (element *Box) freeSpace () (space float64, nExpanding float64) {
 		if entry.expand {
 			nExpanding ++;
 		} else {
-			space -= float64(entry.minimum)
+			space -= float64(entry.minSize)
 		}
 	}
 
@@ -204,7 +205,7 @@ func (element *Box) updateMinimumSize () {
 		
 		key   := element.entity.Child(index)
 		entry := element.scratch[key]
-		entry.minimum = float64(childSize)
+		entry.minSize = float64(childSize)
 		element.scratch[key] = entry
 		
 		if childBreadth > breadth {

elements/containers/document.go

@@ -0,0 +1,235 @@
+package containers
+
+import "image"
+import "git.tebibyte.media/sashakoshka/tomo"
+import "git.tebibyte.media/sashakoshka/tomo/canvas"
+import "git.tebibyte.media/sashakoshka/tomo/shatter"
+import "git.tebibyte.media/sashakoshka/tomo/default/theme"
+
+type documentEntity interface {
+	tomo.ContainerEntity
+	tomo.ScrollableEntity
+}
+
+type Document struct {
+	entity documentEntity
+	
+	scratch       map[tomo.Element] scratchEntry
+	scroll        image.Point
+	contentBounds image.Rectangle
+
+	theme theme.Wrapped
+	
+	onScrollBoundsChange func ()
+}
+
+func NewDocument () (element *Document) {
+	element = &Document { }
+	element.scratch = make(map[tomo.Element] scratchEntry)
+	element.theme.Case = tomo.C("tomo", "document")
+	element.entity = tomo.NewEntity(element).(documentEntity)
+	return
+}
+
+func (element *Document) Entity () tomo.Entity {
+	return element.entity
+}
+
+func (element *Document) Draw (destination canvas.Canvas) {
+	rocks := make([]image.Rectangle, element.entity.CountChildren())
+	for index := 0; index < element.entity.CountChildren(); index ++ {
+		rocks[index] = element.entity.Child(index).Entity().Bounds()
+	}
+
+	tiles := shatter.Shatter(element.entity.Bounds(), rocks...)
+	for _, tile := range tiles {
+		element.entity.DrawBackground(canvas.Cut(destination, tile))
+	}
+}
+
+func (element *Document) Layout () {
+	margin := element.theme.Margin(tomo.PatternBackground)
+	padding := element.theme.Padding(tomo.PatternBackground)
+	bounds := padding.Apply(element.entity.Bounds())
+	element.contentBounds = image.Rectangle { }
+
+	dot := bounds.Min.Sub(element.scroll)
+	xStart := dot.X
+	rowHeight := 0
+
+	nextLine := func () {
+		dot.X = xStart
+		dot.Y += margin.Y
+		dot.Y += rowHeight
+		rowHeight = 0
+	}
+	
+	for index := 0; index < element.entity.CountChildren(); index ++ {
+		child := element.entity.Child(index)
+		entry := element.scratch[child]
+		
+		if dot.X > xStart && entry.expand {
+			nextLine()
+		}
+	
+		width  := int(entry.minBreadth)
+		height := int(entry.minSize)
+		if width + dot.X > bounds.Dx() && !entry.expand {
+			nextLine()
+		}
+		if width < bounds.Dx() && entry.expand {
+			width = bounds.Dx()
+		}
+		if typedChild, ok := child.(tomo.Flexible); ok {
+			height = typedChild.FlexibleHeightFor(width)
+		}
+		if rowHeight < height {
+			rowHeight = height
+		}
+
+		childBounds := tomo.Bounds (
+			dot.X, dot.Y,
+			width, height)
+		element.entity.PlaceChild(index, childBounds)
+		element.contentBounds = element.contentBounds.Union(childBounds)
+		
+		if entry.expand {
+			nextLine()
+		} else {
+			dot.X += width + margin.X
+		}
+	}
+	
+	element.contentBounds =
+		element.contentBounds.Sub(element.contentBounds.Min)
+		
+	element.entity.NotifyScrollBoundsChange()
+	if element.onScrollBoundsChange != nil {
+		element.onScrollBoundsChange()
+	}
+}
+
+func (element *Document) Adopt (child tomo.Element, expand bool) {
+	element.entity.Adopt(child)
+	element.scratch[child] = scratchEntry { expand: expand }
+	element.updateMinimumSize()
+	element.entity.Invalidate()
+	element.entity.InvalidateLayout()
+}
+
+func (element *Document) Disown (child tomo.Element) {
+	index := element.entity.IndexOf(child)
+	if index < 0 { return }
+	element.entity.Disown(index)
+	delete(element.scratch, child)
+	element.updateMinimumSize()
+	element.entity.Invalidate()
+	element.entity.InvalidateLayout()
+}
+
+func (element *Document) DisownAll () {
+	func () {
+		for index := 0; index < element.entity.CountChildren(); index ++ {
+			index := index
+			defer element.entity.Disown(index)
+		}
+	} ()
+	element.scratch = make(map[tomo.Element] scratchEntry)
+	element.updateMinimumSize()
+	element.entity.Invalidate()
+	element.entity.InvalidateLayout()
+}
+
+func (element *Document) HandleChildMinimumSizeChange (child tomo.Element) {
+	element.updateMinimumSize()
+	element.entity.Invalidate()
+	element.entity.InvalidateLayout()
+}
+
+func (element *Document) HandleChildFlexibleHeightChange (child tomo.Flexible) {
+	element.updateMinimumSize()
+	element.entity.Invalidate()
+	element.entity.InvalidateLayout()
+}
+
+func (element *Document) DrawBackground (destination canvas.Canvas) {
+	element.entity.DrawBackground(destination)
+}
+
+// SetTheme sets the element's theme.
+func (element *Document) SetTheme (theme tomo.Theme) {
+	if theme == element.theme.Theme { return }
+	element.theme.Theme = theme
+	element.updateMinimumSize()
+	element.entity.Invalidate()
+	element.entity.InvalidateLayout()
+}
+
+
+// ScrollContentBounds returns the full content size of the element.
+func (element *Document) ScrollContentBounds () image.Rectangle {
+	return element.contentBounds
+}
+
+// ScrollViewportBounds returns the size and position of the element's
+// viewport relative to ScrollBounds.
+func (element *Document) ScrollViewportBounds () image.Rectangle {
+	padding := element.theme.Padding(tomo.PatternBackground)
+	bounds  := padding.Apply(element.entity.Bounds())
+	bounds   = bounds.Sub(bounds.Min).Add(element.scroll)
+	return bounds
+}
+
+// ScrollTo scrolls the viewport to the specified point relative to
+// ScrollBounds.
+func (element *Document) ScrollTo (position image.Point) {
+	if position.Y < 0 {
+		position.Y = 0
+	}
+	maxScrollHeight := element.maxScrollHeight()
+	if position.Y > maxScrollHeight {
+		position.Y = maxScrollHeight
+	}
+	element.scroll = position
+	element.entity.Invalidate()
+	element.entity.InvalidateLayout()
+}
+
+// OnScrollBoundsChange sets a function to be called when the element's viewport
+// bounds, content bounds, or scroll axes change.
+func (element *Document) OnScrollBoundsChange (callback func ()) {
+	element.onScrollBoundsChange = callback
+}
+
+// ScrollAxes returns the supported axes for scrolling.
+func (element *Document) ScrollAxes () (horizontal, vertical bool) {
+	return false, true
+}
+
+func (element *Document) maxScrollHeight () (height int) {
+	padding := element.theme.Padding(tomo.PatternSunken)
+	viewportHeight := element.entity.Bounds().Dy() - padding.Vertical()
+	height = element.contentBounds.Dy() - viewportHeight
+	if height < 0 { height = 0 }
+	return
+}
+
+func (element *Document) updateMinimumSize () {
+	padding := element.theme.Padding(tomo.PatternBackground)
+	minimumWidth := 0
+	for index := 0; index < element.entity.CountChildren(); index ++ {
+		width, height := element.entity.ChildMinimumSize(index)
+		if width > minimumWidth {
+			minimumWidth = width
+		}
+		
+		key   := element.entity.Child(index)
+		entry := element.scratch[key]
+		entry.minSize    = float64(height)
+		entry.minBreadth = float64(width)
+		element.scratch[key] = entry
+	}
+	element.entity.SetMinimumSize (
+		minimumWidth + padding.Horizontal(),
+		padding.Vertical())
+}

examples/align/main.go

@@ -11,11 +11,11 @@ func main () {
 }
 
 func run () {
-	window, _ := tomo.NewWindow(tomo.Bounds(0, 0, 0, 0))
+	window, _ := tomo.NewWindow(tomo.Bounds(0, 0, 256, 256))
 	window.SetTitle("Text alignment")
 
-	container := containers.NewDocumentContainer()
-	scrollContainer := containers.NewScrollContainer(false, true)
+	container := containers.NewDocument()
+	scrollContainer := containers.NewScroll(false, true)
 	scrollContainer.Adopt(container)
 	window.Adopt(scrollContainer)
 

examples/documentContainer/main.go

@@ -22,8 +22,8 @@ func run () {
 	file.Close()
 	if err != nil { panic(err.Error()); return  }
 
-	scrollContainer := containers.NewScrollContainer(false, true)
-	document := containers.NewDocumentContainer()
+	scrollContainer := containers.NewScroll(false, true)
+	document := containers.NewDocument()
 
 	document.Adopt (elements.NewLabel (
 		"A document container is a vertically stacked container " +