package elements 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 { container entity documentEntity scroll image.Point contentBounds image.Rectangle theme theme.Wrapped onScrollBoundsChange func () } func NewDocument (children ...tomo.Element) (element *Document) { element = &Document { } element.theme.Case = tomo.C("tomo", "document") element.entity = tomo.NewEntity(element).(documentEntity) element.container.entity = element.entity element.minimumSize = element.updateMinimumSize element.init() element.Adopt(children...) return } 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 () { if element.scroll.Y > element.maxScrollHeight() { element.scroll.Y = element.maxScrollHeight() } 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.Max.X && !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 (children ...tomo.Element) { element.adopt(true, children...) } func (element *Document) AdoptInline (children ...tomo.Element) { element.adopt(false, children...) } 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()) }