package basicLayouts import "image" import "git.tebibyte.media/sashakoshka/tomo/layouts" import "git.tebibyte.media/sashakoshka/tomo/elements" // Vertical arranges elements vertically. Elements at the start of the entry // list will be positioned at the top, and elements at the end of the entry list // will positioned at the bottom. All elements have the same width. type Vertical struct { // If Gap is true, a gap will be placed between each element. Gap bool // If Pad is true, there will be padding running along the inside of the // layout's border. Pad bool } // Arrange arranges a list of entries vertically. func (layout Vertical) Arrange ( entries []layouts.LayoutEntry, margin int, bounds image.Rectangle, ) { if layout.Pad { bounds = bounds.Inset(margin) } // count the number of expanding elements and the amount of free space // for them to collectively occupy, while gathering minimum heights. freeSpace := bounds.Dy() minimumHeights := make([]int, len(entries)) expandingElements := 0 for index, entry := range entries { var entryMinHeight int if child, flexible := entry.Element.(elements.Flexible); flexible { entryMinHeight = child.FlexibleHeightFor(bounds.Dx()) } else { _, entryMinHeight = entry.MinimumSize() } minimumHeights[index] = entryMinHeight if entry.Expand { expandingElements ++ } else { freeSpace -= entryMinHeight } if index > 0 && layout.Gap { freeSpace -= margin } } expandingElementHeight := 0 if expandingElements > 0 { expandingElementHeight = freeSpace / expandingElements } // set the size and position of each element dot := bounds.Min for index, entry := range entries { if index > 0 && layout.Gap { dot.Y += margin } entry.Bounds.Min = dot entryHeight := 0 if entry.Expand { entryHeight = expandingElementHeight } else { entryHeight = minimumHeights[index] } dot.Y += entryHeight entryBounds := entry.Bounds entry.Bounds.Max = entryBounds.Min.Add(image.Pt(bounds.Dx(), entryHeight)) entries[index] = entry } } // MinimumSize returns the minimum width and height that will be needed to // arrange the given list of entries. func (layout Vertical) MinimumSize ( entries []layouts.LayoutEntry, margin int, ) ( width, height int, ) { for index, entry := range entries { entryWidth, entryHeight := entry.MinimumSize() if entryWidth > width { width = entryWidth } height += entryHeight if layout.Gap && index > 0 { height += margin } } if layout.Pad { width += margin * 2 height += margin * 2 } return } // FlexibleHeightFor Returns the minimum height the layout needs to lay out the // specified elements at the given width, taking into account flexible elements. func (layout Vertical) FlexibleHeightFor ( entries []layouts.LayoutEntry, margin int, width int, ) ( height int, ) { if layout.Pad { width -= margin * 2 height += margin * 2 } for index, entry := range entries { child, flexible := entry.Element.(elements.Flexible) if flexible { height += child.FlexibleHeightFor(width) } else { _, entryHeight := entry.MinimumSize() height += entryHeight } if layout.Gap && index > 0 { height += margin } } return }