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tomo-old/layouts/basic/dialog.go

188 lines
4.6 KiB
Go

package basicLayouts
import "image"
import "git.tebibyte.media/sashakoshka/tomo/layouts"
import "git.tebibyte.media/sashakoshka/tomo/elements"
// Dialog arranges elements in the form of a dialog box. The first element is
// positioned above as the main focus of the dialog, and is set to expand
// regardless of whether it is expanding or not. The remaining elements are
// arranged at the bottom in a row called the control row, which is aligned to
// the right, the last element being the rightmost one.
type Dialog 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 into a dialog.
func (layout Dialog) Arrange (
entries []layouts.LayoutEntry,
margin int,
bounds image.Rectangle,
) {
if layout.Pad { bounds = bounds.Inset(margin) }
controlRowWidth, controlRowHeight := 0, 0
if len(entries) > 1 {
controlRowWidth,
controlRowHeight = layout.minimumSizeOfControlRow (
entries[1:], margin)
}
if len(entries) > 0 {
main := entries[0]
main.Bounds.Min = bounds.Min
mainHeight := bounds.Dy() - controlRowHeight
if layout.Gap {
mainHeight -= margin
}
main.Bounds.Max = main.Bounds.Min.Add(image.Pt(bounds.Dx(), mainHeight))
entries[0] = main
}
if len(entries) > 1 {
freeSpace := bounds.Dx()
expandingElements := 0
// count the number of expanding elements and the amount of free
// space for them to collectively occupy
for index, entry := range entries[1:] {
if entry.Expand {
expandingElements ++
} else {
entryMinWidth, _ := entry.MinimumSize()
freeSpace -= entryMinWidth
}
if index > 0 && layout.Gap {
freeSpace -= margin
}
}
expandingElementWidth := 0
if expandingElements > 0 {
expandingElementWidth = freeSpace / expandingElements
}
// determine starting position and dimensions for control row
dot := image.Pt(bounds.Min.X, bounds.Max.Y - controlRowHeight)
if expandingElements == 0 {
dot.X = bounds.Max.X - controlRowWidth
}
// set the size and position of each element in the control row
for index, entry := range entries[1:] {
if index > 0 && layout.Gap { dot.X += margin }
entry.Bounds.Min = dot
entryWidth := 0
if entry.Expand {
entryWidth = expandingElementWidth
} else {
entryWidth, _ = entry.MinimumSize()
}
dot.X += entryWidth
entryBounds := entry.Bounds
if entryBounds.Dy() != controlRowHeight ||
entryBounds.Dx() != entryWidth {
entry.Bounds.Max = entryBounds.Min.Add (
image.Pt(entryWidth, controlRowHeight))
}
entries[index + 1] = entry
}
}
}
// MinimumSize returns the minimum width and height that will be needed to
// arrange the given list of entries.
func (layout Dialog) MinimumSize (
entries []layouts.LayoutEntry,
margin int,
) (
width, height int,
) {
if len(entries) > 0 {
mainChildHeight := 0
width, mainChildHeight = entries[0].MinimumSize()
height += mainChildHeight
}
if len(entries) > 1 {
if layout.Gap { height += margin }
additionalWidth,
additionalHeight := layout.minimumSizeOfControlRow (
entries[1:], margin)
height += additionalHeight
if additionalWidth > width {
width = additionalWidth
}
}
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 Dialog) FlexibleHeightFor (
entries []layouts.LayoutEntry,
margin int,
width int,
) (
height int,
) {
if layout.Pad {
width -= margin * 2
}
if len(entries) > 0 {
mainChildHeight := 0
if child, flexible := entries[0].Element.(elements.Flexible); flexible {
mainChildHeight = child.FlexibleHeightFor(width)
} else {
_, mainChildHeight = entries[0].MinimumSize()
}
height += mainChildHeight
}
if len(entries) > 1 {
if layout.Gap { height += margin }
_, additionalHeight := layout.minimumSizeOfControlRow (
entries[1:], margin)
height += additionalHeight
}
if layout.Pad {
height += margin * 2
}
return
}
// TODO: possibly flatten this method to account for flexible elements within
// the control row.
func (layout Dialog) minimumSizeOfControlRow (
entries []layouts.LayoutEntry,
margin int,
) (
width, height int,
) {
for index, entry := range entries {
entryWidth, entryHeight := entry.MinimumSize()
if entryHeight > height {
height = entryHeight
}
width += entryWidth
if layout.Gap && index > 0 {
width += margin
}
}
return
}