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tomo-old/layouts/basic/vertical.go

97 lines
2.4 KiB
Go

package basicLayouts
import "image"
import "git.tebibyte.media/sashakoshka/tomo/artist"
import "git.tebibyte.media/sashakoshka/tomo/layouts"
// 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 image.Point,
padding artist.Inset,
bounds image.Rectangle,
) {
if layout.Pad { bounds = padding.Apply(bounds) }
// 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 {
_, entryMinHeight := entry.MinimumSize()
minimumHeights[index] = entryMinHeight
if entry.Expand {
expandingElements ++
} else {
freeSpace -= entryMinHeight
}
if index > 0 && layout.Gap {
freeSpace -= margin.Y
}
}
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.Y }
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 image.Point,
padding artist.Inset,
) (
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.Y
}
}
if layout.Pad {
width += padding.Horizontal()
height += padding.Vertical()
}
return
}