func (l *BoxLayout) Update(reset bool) error {
if l.container == nil {
return nil
}
if reset {
l.resetNeeded = true
}
if l.container.Suspended() {
return nil
}
if l.resetNeeded {
l.resetNeeded = false
// Make GC happy.
l.cleanupStretchFactors()
}
// Begin by finding out which widgets we care about.
widgets := l.widgets()
// Prepare some useful data.
var greedyNonSpacerCount int
var greedySpacerCount int
var stretchFactorsTotal [3]int
stretchFactors := make([]int, len(widgets))
var minSizesRemaining int
minSizes := make([]int, len(widgets))
maxSizes := make([]int, len(widgets))
sizes := make([]int, len(widgets))
prefSizes2 := make([]int, len(widgets))
growable2 := make([]bool, len(widgets))
sortedWidgetInfo := widgetInfoList(make([]widgetInfo, len(widgets)))
for i, widget := range widgets {
sf := l.hwnd2StretchFactor[widget.Handle()]
if sf == 0 {
sf = 1
}
stretchFactors[i] = sf
flags := widget.LayoutFlags()
min := widget.MinSize()
max := widget.MaxSize()
minHint := widget.MinSizeHint()
pref := widget.SizeHint()
if l.orientation == Horizontal {
growable2[i] = flags&GrowableVert > 0
minSizes[i] = maxi(min.Width, minHint.Width)
if max.Width > 0 {
maxSizes[i] = max.Width
} else if pref.Width > 0 && flags&GrowableHorz == 0 {
maxSizes[i] = pref.Width
} else {
maxSizes[i] = 32768
}
prefSizes2[i] = pref.Height
sortedWidgetInfo[i].greedy = flags&GreedyHorz > 0
} else {
growable2[i] = flags&GrowableHorz > 0
minSizes[i] = maxi(min.Height, minHint.Height)
if max.Height > 0 {
maxSizes[i] = max.Height
} else if pref.Height > 0 && flags&GrowableVert == 0 {
maxSizes[i] = pref.Height
} else {
maxSizes[i] = 32768
}
prefSizes2[i] = pref.Width
sortedWidgetInfo[i].greedy = flags&GreedyVert > 0
}
sortedWidgetInfo[i].index = i
sortedWidgetInfo[i].minSize = minSizes[i]
sortedWidgetInfo[i].maxSize = maxSizes[i]
sortedWidgetInfo[i].stretch = sf
sortedWidgetInfo[i].widget = widget
minSizesRemaining += minSizes[i]
if sortedWidgetInfo[i].greedy {
if _, isSpacer := widget.(*Spacer); !isSpacer {
greedyNonSpacerCount++
stretchFactorsTotal[0] += sf
} else {
greedySpacerCount++
stretchFactorsTotal[1] += sf
}
} else {
stretchFactorsTotal[2] += sf
}
}
sort.Sort(sortedWidgetInfo)
cb := l.container.ClientBounds()
var start1, start2, space1, space2 int
if l.orientation == Horizontal {
start1 = cb.X + l.margins.HNear
start2 = cb.Y + l.margins.VNear
space1 = cb.Width - l.margins.HNear - l.margins.HFar
space2 = cb.Height - l.margins.VNear - l.margins.VFar
} else {
start1 = cb.Y + l.margins.VNear
start2 = cb.X + l.margins.HNear
space1 = cb.Height - l.margins.VNear - l.margins.VFar
space2 = cb.Width - l.margins.HNear - l.margins.HFar
}
// Now calculate widget primary axis sizes.
spacingRemaining := l.spacing * (len(widgets) - 1)
offsets := [3]int{0, greedyNonSpacerCount, greedyNonSpacerCount + greedySpacerCount}
counts := [3]int{greedyNonSpacerCount, greedySpacerCount, len(widgets) - greedyNonSpacerCount - greedySpacerCount}
for i := 0; i < 3; i++ {
stretchFactorsRemaining := stretchFactorsTotal[i]
for j := 0; j < counts[i]; j++ {
info := sortedWidgetInfo[offsets[i]+j]
k := info.index
stretch := stretchFactors[k]
min := info.minSize
max := info.maxSize
size := min
if min < max {
excessSpace := float64(space1 - minSizesRemaining - spacingRemaining)
size += int(excessSpace * float64(stretch) / float64(stretchFactorsRemaining))
if size < min {
size = min
} else if size > max {
size = max
}
}
sizes[k] = size
minSizesRemaining -= min
stretchFactorsRemaining -= stretch
space1 -= (size + l.spacing)
spacingRemaining -= l.spacing
}
}
// Finally position widgets.
hdwp := win.BeginDeferWindowPos(int32(len(widgets)))
if hdwp == 0 {
return lastError("BeginDeferWindowPos")
}
excessTotal := space1 - minSizesRemaining - spacingRemaining
excessShare := excessTotal / (len(widgets) + 1)
p1 := start1
for i, widget := range widgets {
p1 += excessShare
s1 := sizes[i]
var s2 int
if growable2[i] {
s2 = space2
} else {
s2 = prefSizes2[i]
}
p2 := start2 + (space2-s2)/2
var x, y, w, h int
if l.orientation == Horizontal {
x, y, w, h = p1, p2, s1, s2
} else {
x, y, w, h = p2, p1, s2, s1
}
if hdwp = win.DeferWindowPos(
hdwp,
widget.Handle(),
0,
int32(x),
int32(y),
int32(w),
int32(h),
win.SWP_NOACTIVATE|win.SWP_NOOWNERZORDER|win.SWP_NOZORDER); hdwp == 0 {
return lastError("DeferWindowPos")
}
p1 += s1 + l.spacing
}
if !win.EndDeferWindowPos(hdwp) {
return lastError("EndDeferWindowPos")
}
return nil
}
func (l *GridLayout) Update(reset bool) error {
if l.container == nil {
return nil
}
if reset {
l.resetNeeded = true
}
if l.container.Suspended() {
return nil
}
if l.resetNeeded {
l.resetNeeded = false
l.cleanup()
}
widths := l.sectionSizes(Horizontal)
heights := l.sectionSizes(Vertical)
hdwp := win.BeginDeferWindowPos(int32(l.container.Children().Len()))
if hdwp == 0 {
return lastError("BeginDeferWindowPos")
}
for widget, info := range l.widget2Info {
x := l.margins.HNear
for i := 0; i < info.cell.column; i++ {
x += widths[i] + l.spacing
}
y := l.margins.VNear
for i := 0; i < info.cell.row; i++ {
y += heights[i] + l.spacing
}
w := 0
for i := info.cell.column; i < info.cell.column+info.spanHorz; i++ {
w += widths[i]
if i > info.cell.column {
w += l.spacing
}
}
h := 0
for i := info.cell.row; i < info.cell.row+info.spanVert; i++ {
h += heights[i]
if i > info.cell.row {
h += l.spacing
}
}
if lf := widget.LayoutFlags(); lf&GrowableHorz == 0 || lf&GrowableVert == 0 {
hint := widget.SizeHint()
if lf&GrowableHorz == 0 {
w = hint.Width
}
if lf&GrowableVert == 0 {
h = hint.Height
}
}
if hdwp = win.DeferWindowPos(
hdwp,
widget.Handle(),
0,
int32(x),
int32(y),
int32(w),
int32(h),
win.SWP_NOACTIVATE|win.SWP_NOOWNERZORDER|win.SWP_NOZORDER); hdwp == 0 {
return lastError("DeferWindowPos")
}
}
if !win.EndDeferWindowPos(hdwp) {
return lastError("EndDeferWindowPos")
}
return nil
}
func (l *splitterLayout) Update(reset bool) error {
if l.container == nil {
return newError("container required")
}
if reset {
l.resetNeeded = true
}
if l.container.Suspended() {
return nil
}
if l.resetNeeded {
l.resetNeeded = false
l.reset()
}
widgets := l.container.Children().items
splitter := l.container.(*Splitter)
handleWidth := splitter.HandleWidth()
sizes := make([]int, len(widgets))
cb := splitter.ClientBounds()
space1 := l.spaceForRegularWidgets()
var space2 int
if l.orientation == Horizontal {
space2 = cb.Height
} else {
space2 = cb.Width
}
for i := range widgets {
j := i/2 + i%2
if i%2 == 0 {
sizes[i] = int(float64(space1) * l.fractions[j])
} else {
sizes[i] = handleWidth
}
}
hdwp := win.BeginDeferWindowPos(int32(len(widgets)))
if hdwp == 0 {
return lastError("BeginDeferWindowPos")
}
p1 := 0
for i, widget := range widgets {
var s1 int
if i == len(widgets)-1 {
s1 = space1 + len(widgets)/2*handleWidth - p1
} else {
s1 = sizes[i]
}
var x, y, w, h int
if l.orientation == Horizontal {
x, y, w, h = p1, 0, s1, space2
} else {
x, y, w, h = 0, p1, space2, s1
}
if hdwp = win.DeferWindowPos(
hdwp,
widget.Handle(),
0,
int32(x),
int32(y),
int32(w),
int32(h),
win.SWP_NOACTIVATE|win.SWP_NOOWNERZORDER|win.SWP_NOZORDER); hdwp == 0 {
return lastError("DeferWindowPos")
}
p1 += s1
}
if !win.EndDeferWindowPos(hdwp) {
return lastError("EndDeferWindowPos")
}
return nil
}