package basic import "image" import "git.tebibyte.media/sashakoshka/tomo" import "git.tebibyte.media/sashakoshka/tomo/theme" import "git.tebibyte.media/sashakoshka/tomo/artist" import "git.tebibyte.media/sashakoshka/tomo/elements/core" var scrollContainerCase = theme.C("basic", "scrollContainer") var scrollBarHorizontalCase = theme.C("basic", "scrollBarHorizontal") var scrollBarVerticalCase = theme.C("basic", "scrollBarVertical") // ScrollContainer is a container that is capable of holding a scrollable // element. type ScrollContainer struct { *core.Core core core.CoreControl selected bool child tomo.Scrollable childWidth, childHeight int horizontal struct { exists bool enabled bool dragging bool dragOffset int gutter image.Rectangle track image.Rectangle bar image.Rectangle } vertical struct { exists bool enabled bool dragging bool dragOffset int gutter image.Rectangle track image.Rectangle bar image.Rectangle } onSelectionRequest func () (granted bool) onSelectionMotionRequest func (tomo.SelectionDirection) (granted bool) } // NewScrollContainer creates a new scroll container with the specified scroll // bars. func NewScrollContainer (horizontal, vertical bool) (element *ScrollContainer) { element = &ScrollContainer { } element.Core, element.core = core.NewCore(element) element.updateMinimumSize() element.horizontal.exists = horizontal element.vertical.exists = vertical return } // Resize resizes the scroll box. func (element *ScrollContainer) Resize (width, height int) { element.core.AllocateCanvas(width, height) element.recalculate() element.child.Resize ( element.childWidth, element.childHeight) element.draw() } // Adopt adds a scrollable element to the scroll container. The container can // only contain one scrollable element at a time, and when a new one is adopted // it replaces the last one. func (element *ScrollContainer) Adopt (child tomo.Scrollable) { // disown previous child if it exists if element.child != nil { element.clearChildEventHandlers(child) } // adopt new child element.child = child if child != nil { child.OnDamage(element.childDamageCallback) child.OnMinimumSizeChange(element.updateMinimumSize) child.OnScrollBoundsChange(element.childScrollBoundsChangeCallback) if newChild, ok := child.(tomo.Selectable); ok { newChild.OnSelectionRequest ( element.childSelectionRequestCallback) newChild.OnSelectionMotionRequest ( element.childSelectionMotionRequestCallback) } // TODO: somehow inform the core that we do not in fact want to // redraw the element. element.updateMinimumSize() element.horizontal.enabled, element.vertical.enabled = element.child.ScrollAxes() if element.core.HasImage() { element.child.Resize ( element.childWidth, element.childHeight) element.core.DamageAll() } } } func (element *ScrollContainer) HandleKeyDown (key tomo.Key, modifiers tomo.Modifiers) { if child, ok := element.child.(tomo.KeyboardTarget); ok { child.HandleKeyDown(key, modifiers) } } func (element *ScrollContainer) HandleKeyUp (key tomo.Key, modifiers tomo.Modifiers) { if child, ok := element.child.(tomo.KeyboardTarget); ok { child.HandleKeyUp(key, modifiers) } } func (element *ScrollContainer) HandleMouseDown (x, y int, button tomo.Button) { point := image.Pt(x, y) if point.In(element.horizontal.bar) { element.horizontal.dragging = true element.horizontal.dragOffset = point.Sub(element.horizontal.bar.Min).X element.dragHorizontalBar(point) } else if point.In(element.horizontal.gutter) { // FIXME: x backend and scroll container should pull these // values from the same place if x > element.horizontal.bar.Min.X { element.scrollChildBy(16, 0) } else { element.scrollChildBy(-16, 0) } } else if point.In(element.vertical.bar) { element.vertical.dragging = true element.vertical.dragOffset = point.Sub(element.vertical.bar.Min).Y element.dragVerticalBar(point) } else if point.In(element.vertical.gutter) { if y > element.vertical.bar.Min.Y { element.scrollChildBy(0, 16) } else { element.scrollChildBy(0, -16) } } else if child, ok := element.child.(tomo.MouseTarget); ok { child.HandleMouseDown(x, y, button) } } func (element *ScrollContainer) HandleMouseUp (x, y int, button tomo.Button) { if element.horizontal.dragging { element.horizontal.dragging = false element.drawHorizontalBar() element.core.DamageRegion(element.horizontal.bar) } else if element.vertical.dragging { element.vertical.dragging = false element.drawVerticalBar() element.core.DamageRegion(element.vertical.bar) } else if child, ok := element.child.(tomo.MouseTarget); ok { child.HandleMouseUp(x, y, button) } } func (element *ScrollContainer) HandleMouseMove (x, y int) { if element.horizontal.dragging { element.dragHorizontalBar(image.Pt(x, y)) } else if element.vertical.dragging { element.dragVerticalBar(image.Pt(x, y)) } else if child, ok := element.child.(tomo.MouseTarget); ok { child.HandleMouseMove(x, y) } } func (element *ScrollContainer) HandleMouseScroll ( x, y int, deltaX, deltaY float64, ) { element.scrollChildBy(int(deltaX), int(deltaY)) } func (element *ScrollContainer) scrollChildBy (x, y int) { if element.child == nil { return } scrollPoint := element.child.ScrollViewportBounds().Min. Add(image.Pt(x, y)) element.child.ScrollTo(scrollPoint) } func (element *ScrollContainer) Selected () (selected bool) { return element.selected } func (element *ScrollContainer) Select () { if element.onSelectionRequest != nil { element.onSelectionRequest() } } func (element *ScrollContainer) HandleSelection ( direction tomo.SelectionDirection, ) ( accepted bool, ) { if child, ok := element.child.(tomo.Selectable); ok { element.selected = true return child.HandleSelection(direction) } else { element.selected = false return false } } func (element *ScrollContainer) HandleDeselection () { if child, ok := element.child.(tomo.Selectable); ok { child.HandleDeselection() } element.selected = false } func (element *ScrollContainer) OnSelectionRequest (callback func () (granted bool)) { element.onSelectionRequest = callback } func (element *ScrollContainer) OnSelectionMotionRequest ( callback func (direction tomo.SelectionDirection) (granted bool), ) { element.onSelectionMotionRequest = callback } func (element *ScrollContainer) childDamageCallback (region tomo.Canvas) { element.core.DamageRegion(artist.Paste(element, region, image.Point { })) } func (element *ScrollContainer) childSelectionRequestCallback () (granted bool) { child, ok := element.child.(tomo.Selectable) if !ok { return false } if element.onSelectionRequest != nil && element.onSelectionRequest() { child.HandleSelection(tomo.SelectionDirectionNeutral) return true } else { return false } } func (element *ScrollContainer) childSelectionMotionRequestCallback ( direction tomo.SelectionDirection, ) ( granted bool, ) { if element.onSelectionMotionRequest == nil { return } return element.onSelectionMotionRequest(direction) } func (element *ScrollContainer) clearChildEventHandlers (child tomo.Scrollable) { child.OnDamage(nil) child.OnMinimumSizeChange(nil) child.OnScrollBoundsChange(nil) if child0, ok := child.(tomo.Selectable); ok { child0.OnSelectionRequest(nil) child0.OnSelectionMotionRequest(nil) if child0.Selected() { child0.HandleDeselection() } } if child0, ok := child.(tomo.Flexible); ok { child0.OnFlexibleHeightChange(nil) } } func (element *ScrollContainer) recalculate () { _, gutterInsetHorizontal := theme.GutterPattern(theme.PatternState { Case: scrollBarHorizontalCase, }) _, gutterInsetVertical := theme.GutterPattern(theme.PatternState { Case: scrollBarHorizontalCase, }) horizontal := &element.horizontal vertical := &element.vertical bounds := element.Bounds() thicknessHorizontal := theme.HandleWidth() + gutterInsetHorizontal[3] + gutterInsetHorizontal[1] thicknessVertical := theme.HandleWidth() + gutterInsetVertical[3] + gutterInsetVertical[1] // calculate child size element.childWidth = bounds.Dx() element.childHeight = bounds.Dy() // reset bounds horizontal.gutter = image.Rectangle { } vertical.gutter = image.Rectangle { } horizontal.bar = image.Rectangle { } vertical.bar = image.Rectangle { } // if enabled, give substance to the gutters if horizontal.exists { horizontal.gutter.Min.Y = bounds.Max.Y - thicknessHorizontal horizontal.gutter.Max.X = bounds.Max.X horizontal.gutter.Max.Y = bounds.Max.Y if vertical.exists { horizontal.gutter.Max.X -= thicknessVertical } element.childHeight -= thicknessHorizontal horizontal.track = gutterInsetHorizontal.Apply(horizontal.gutter) } if vertical.exists { vertical.gutter.Min.X = bounds.Max.X - thicknessVertical vertical.gutter.Max.X = bounds.Max.X vertical.gutter.Max.Y = bounds.Max.Y if horizontal.exists { vertical.gutter.Max.Y -= thicknessHorizontal } element.childWidth -= thicknessVertical vertical.track = gutterInsetVertical.Apply(vertical.gutter) } // if enabled, calculate the positions of the bars contentBounds := element.child.ScrollContentBounds() viewportBounds := element.child.ScrollViewportBounds() if horizontal.exists && horizontal.enabled { horizontal.bar.Min.Y = horizontal.track.Min.Y horizontal.bar.Max.Y = horizontal.track.Max.Y scale := float64(horizontal.track.Dx()) / float64(contentBounds.Dx()) horizontal.bar.Min.X = int(float64(viewportBounds.Min.X) * scale) horizontal.bar.Max.X = int(float64(viewportBounds.Max.X) * scale) horizontal.bar.Min.X += horizontal.track.Min.X horizontal.bar.Max.X += horizontal.track.Min.X } if vertical.exists && vertical.enabled { vertical.bar.Min.X = vertical.track.Min.X vertical.bar.Max.X = vertical.track.Max.X scale := float64(vertical.track.Dy()) / float64(contentBounds.Dy()) vertical.bar.Min.Y = int(float64(viewportBounds.Min.Y) * scale) vertical.bar.Max.Y = int(float64(viewportBounds.Max.Y) * scale) vertical.bar.Min.Y += vertical.track.Min.Y vertical.bar.Max.Y += vertical.track.Min.Y } // if the scroll bars are out of bounds, don't display them. if horizontal.bar.Dx() >= horizontal.track.Dx() { horizontal.bar = image.Rectangle { } } if vertical.bar.Dy() >= vertical.track.Dy() { vertical.bar = image.Rectangle { } } } func (element *ScrollContainer) draw () { artist.Paste(element.core, element.child, image.Point { }) deadPattern, _ := theme.DeadPattern(theme.PatternState { Case: scrollContainerCase, }) artist.FillRectangle ( element, deadPattern, image.Rect ( element.vertical.gutter.Min.X, element.horizontal.gutter.Min.Y, element.vertical.gutter.Max.X, element.horizontal.gutter.Max.Y)) element.drawHorizontalBar() element.drawVerticalBar() } func (element *ScrollContainer) drawHorizontalBar () { gutterPattern, _ := theme.GutterPattern (theme.PatternState { Case: scrollBarHorizontalCase, Disabled: !element.horizontal.enabled, }) artist.FillRectangle(element, gutterPattern, element.horizontal.gutter) handlePattern, _ := theme.HandlePattern (theme.PatternState { Case: scrollBarHorizontalCase, Disabled: !element.horizontal.enabled, Pressed: element.horizontal.dragging, }) artist.FillRectangle(element, handlePattern, element.horizontal.bar) } func (element *ScrollContainer) drawVerticalBar () { gutterPattern, _ := theme.GutterPattern (theme.PatternState { Case: scrollBarVerticalCase, Disabled: !element.vertical.enabled, }) artist.FillRectangle(element, gutterPattern, element.vertical.gutter) handlePattern, _ := theme.HandlePattern (theme.PatternState { Case: scrollBarVerticalCase, Disabled: !element.vertical.enabled, Pressed: element.vertical.dragging, }) artist.FillRectangle(element, handlePattern, element.vertical.bar) } func (element *ScrollContainer) dragHorizontalBar (mousePosition image.Point) { scrollX := float64(element.child.ScrollContentBounds().Dx()) / float64(element.horizontal.track.Dx()) * float64(mousePosition.X - element.horizontal.dragOffset) scrollY := element.child.ScrollViewportBounds().Min.Y element.child.ScrollTo(image.Pt(int(scrollX), scrollY)) } func (element *ScrollContainer) dragVerticalBar (mousePosition image.Point) { scrollY := float64(element.child.ScrollContentBounds().Dy()) / float64(element.vertical.track.Dy()) * float64(mousePosition.Y - element.vertical.dragOffset) scrollX := element.child.ScrollViewportBounds().Min.X element.child.ScrollTo(image.Pt(scrollX, int(scrollY))) } func (element *ScrollContainer) updateMinimumSize () { _, gutterInsetHorizontal := theme.GutterPattern(theme.PatternState { Case: scrollBarHorizontalCase, }) _, gutterInsetVertical := theme.GutterPattern(theme.PatternState { Case: scrollBarHorizontalCase, }) thicknessHorizontal := theme.HandleWidth() + gutterInsetHorizontal[3] + gutterInsetHorizontal[1] thicknessVertical := theme.HandleWidth() + gutterInsetVertical[3] + gutterInsetVertical[1] width := thicknessHorizontal height := thicknessVertical if element.child != nil { childWidth, childHeight := element.child.MinimumSize() width += childWidth height += childHeight } element.core.SetMinimumSize(width, height) } func (element *ScrollContainer) childScrollBoundsChangeCallback () { element.horizontal.enabled, element.vertical.enabled = element.child.ScrollAxes() if element.core.HasImage() { element.recalculate() element.drawHorizontalBar() element.drawVerticalBar() element.core.DamageRegion(element.horizontal.gutter) element.core.DamageRegion(element.vertical.gutter) } }