erm/vendor/github.com/lxn/walk/splitter.go

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2021-07-30 22:29:20 +00:00
// Copyright 2010 The Walk Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// +build windows
package walk
import (
"bytes"
"log"
"strconv"
"strings"
"unsafe"
"github.com/lxn/win"
)
const splitterWindowClass = `\o/ Walk_Splitter_Class \o/`
var splitterHandleDraggingBrush *SolidColorBrush
func init() {
AppendToWalkInit(func() {
MustRegisterWindowClass(splitterWindowClass)
splitterHandleDraggingBrush, _ = NewSolidColorBrush(Color(win.GetSysColor(win.COLOR_BTNSHADOW)))
splitterHandleDraggingBrush.wb2info = map[*WindowBase]*windowBrushInfo{nil: nil}
})
}
type Splitter struct {
ContainerBase
handleWidth int
mouseDownPos Point // in native pixels
draggedHandle *splitterHandle
persistent bool
removing bool
}
func newSplitter(parent Container, orientation Orientation) (*Splitter, error) {
layout := newSplitterLayout(Horizontal)
s := &Splitter{
ContainerBase: ContainerBase{
layout: layout,
},
handleWidth: 5,
}
s.children = newWidgetList(s)
layout.container = s
if err := InitWidget(
s,
parent,
splitterWindowClass,
win.WS_VISIBLE,
win.WS_EX_CONTROLPARENT); err != nil {
return nil, err
}
var succeeded bool
defer func() {
if !succeeded {
s.Dispose()
}
}()
s.SetBackground(NullBrush())
if err := s.setOrientation(orientation); err != nil {
return nil, err
}
s.SetPersistent(true)
succeeded = true
return s, nil
}
func NewHSplitter(parent Container) (*Splitter, error) {
return newSplitter(parent, Horizontal)
}
func NewVSplitter(parent Container) (*Splitter, error) {
return newSplitter(parent, Vertical)
}
func (s *Splitter) SetLayout(value Layout) error {
return newError("not supported")
}
func (s *Splitter) HandleWidth() int {
return s.handleWidth
}
func (s *Splitter) SetHandleWidth(value int) error {
if value == s.handleWidth {
return nil
}
if value < 1 {
return newError("invalid handle width")
}
s.handleWidth = value
s.RequestLayout()
return nil
}
func (s *Splitter) Orientation() Orientation {
layout := s.layout.(*splitterLayout)
return layout.Orientation()
}
func (s *Splitter) setOrientation(value Orientation) error {
var cursor Cursor
if value == Horizontal {
cursor = CursorSizeWE()
} else {
cursor = CursorSizeNS()
}
for i, wb := range s.Children().items {
if i%2 == 1 {
wb.window.SetCursor(cursor)
}
}
layout := s.layout.(*splitterLayout)
return layout.SetOrientation(value)
}
func (s *Splitter) updateMarginsForFocusEffect() {
var margins Margins
var parentLayout Layout
if s.parent != nil {
if parentLayout = s.parent.Layout(); parentLayout != nil {
if m := parentLayout.Margins(); m.HNear < 9 || m.HFar < 9 || m.VNear < 9 || m.VFar < 9 {
parentLayout = nil
}
}
}
var affected bool
if FocusEffect != nil {
for _, wb := range s.children.items {
if wb.window.(Widget).GraphicsEffects().Contains(FocusEffect) {
affected = true
break
}
}
}
if affected {
var marginsNeeded bool
for _, wb := range s.children.items {
switch wb.window.(type) {
case *splitterHandle, *TabWidget, Container:
default:
marginsNeeded = true
break
}
}
if marginsNeeded {
margins = Margins{5, 5, 5, 5}
}
}
if parentLayout != nil {
parentLayout.SetMargins(Margins{9 - margins.HNear, 9 - margins.VNear, 9 - margins.HFar, 9 - margins.VFar})
}
s.layout.SetMargins(margins)
}
func (s *Splitter) Persistent() bool {
return s.persistent
}
func (s *Splitter) SetPersistent(value bool) {
s.persistent = value
}
func (s *Splitter) SaveState() error {
buf := bytes.NewBuffer(nil)
count := s.children.Len()
layout := s.Layout().(*splitterLayout)
for i := 0; i < count; i += 2 {
if i > 0 {
buf.WriteString(" ")
}
item := layout.hwnd2Item[s.children.At(i).Handle()]
size := item.oldExplicitSize
if size == 0 {
size = item.size
}
buf.WriteString(strconv.FormatInt(int64(size), 10))
}
s.WriteState(buf.String())
for _, wb := range s.children.items {
if persistable, ok := wb.window.(Persistable); ok {
if err := persistable.SaveState(); err != nil {
return err
}
}
}
return nil
}
func (s *Splitter) RestoreState() error {
childCount := s.children.Len()/2 + 1
if childCount == 0 {
return nil
}
state, err := s.ReadState()
if err != nil {
return err
}
if state == "" {
return nil
}
sizeStrs := strings.Split(state, " ")
// FIXME: Solve this in a better way.
if len(sizeStrs) != childCount {
log.Print("*Splitter.RestoreState: failed due to unexpected child count (FIXME!)")
return nil
}
layout := s.layout.(*splitterLayout)
s.SetSuspended(true)
layout.suspended = true
defer func() {
layout.suspended = false
s.SetSuspended(false)
}()
var space int
size := s.ClientBoundsPixels().Size()
if s.Orientation() == Horizontal {
space = size.Width
} else {
space = size.Height
}
regularSpace := space - layout.spaceUnavailableToRegularWidgets()
for i, wb := range s.children.items {
widget := wb.window.(Widget)
if i%2 == 0 {
j := i/2 + i%2
s := sizeStrs[j]
size, err := strconv.Atoi(s)
if err != nil {
// OK, we probably got old style settings which were stored as fractions.
fraction, err := strconv.ParseFloat(s, 64)
if err != nil {
return err
}
size = int(float64(regularSpace) * fraction)
}
item := layout.hwnd2Item[widget.Handle()]
item.size = size
item.oldExplicitSize = size
}
}
for _, wb := range s.children.items {
if persistable, ok := wb.window.(Persistable); ok {
if err := persistable.RestoreState(); err != nil {
return err
}
}
}
return nil
}
func (s *Splitter) Fixed(widget Widget) bool {
return s.layout.(*splitterLayout).Fixed(widget)
}
func (s *Splitter) SetFixed(widget Widget, fixed bool) error {
item := s.layout.(*splitterLayout).hwnd2Item[widget.Handle()]
if item == nil {
return newError("unknown widget")
}
item.fixed = fixed
if b := widget.BoundsPixels(); fixed && item.size == 0 && (b.Width == 0 || b.Height == 0) {
b.Width, b.Height = 100, 100
widget.SetBoundsPixels(b)
item.size = 100
}
return nil
}
func (s *Splitter) WndProc(hwnd win.HWND, msg uint32, wParam, lParam uintptr) uintptr {
switch msg {
case win.WM_WINDOWPOSCHANGED:
wp := (*win.WINDOWPOS)(unsafe.Pointer(lParam))
if wp.Flags&win.SWP_NOSIZE != 0 {
break
}
layout := s.layout.(*splitterLayout)
layout.resetNeeded = false
for _, item := range layout.hwnd2Item {
item.oldExplicitSize = 0
}
}
return s.ContainerBase.WndProc(hwnd, msg, wParam, lParam)
}
func (s *Splitter) onInsertingWidget(index int, widget Widget) (err error) {
return s.ContainerBase.onInsertingWidget(index, widget)
}
func (s *Splitter) onInsertedWidget(index int, widget Widget) (err error) {
defer func() {
if err != nil {
return
}
s.updateMarginsForFocusEffect()
}()
_, isHandle := widget.(*splitterHandle)
if isHandle {
if s.Orientation() == Horizontal {
widget.SetCursor(CursorSizeWE())
} else {
widget.SetCursor(CursorSizeNS())
}
} else {
layout := s.Layout().(*splitterLayout)
item := &splitterLayoutItem{stretchFactor: 1, wasVisible: true}
layout.hwnd2Item[widget.Handle()] = item
layout.resetNeeded = true
if !layout.suspended && widget.AsWidgetBase().visible {
s.RequestLayout()
}
item.visibleChangedHandle = widget.VisibleChanged().Attach(func() {
if !layout.suspended && widget.AsWidgetBase().visible != item.wasVisible {
layout.resetNeeded = true
s.RequestLayout()
}
})
if s.children.Len()%2 == 0 {
defer func() {
if err != nil {
return
}
var handle *splitterHandle
handle, err = newSplitterHandle(s)
if err != nil {
return
}
closestVisibleWidget := func(offset, direction int) Widget {
index := offset + direction
for index >= 0 && index < len(s.children.items) {
if wb := s.children.items[index]; wb.visible {
return wb.window.(Widget)
}
index += direction
}
return nil
}
handleIndex := index + 1 - index%2
err = s.children.Insert(handleIndex, handle)
if err == nil {
// FIXME: These handlers will be leaked, if widgets get removed.
handle.MouseDown().Attach(func(x, y int, button MouseButton) {
if button != LeftButton {
return
}
s.draggedHandle = handle
s.mouseDownPos = Point{x, y}
handle.SetBackground(splitterHandleDraggingBrush)
})
handle.MouseMove().Attach(func(x, y int, button MouseButton) {
if s.draggedHandle == nil {
return
}
handleIndex := s.children.Index(s.draggedHandle)
bh := s.draggedHandle.BoundsPixels()
prev := closestVisibleWidget(handleIndex, -1)
bp := prev.BoundsPixels()
msep := minSizeEffective(createLayoutItemForWidget(prev))
next := closestVisibleWidget(handleIndex, 1)
bn := next.BoundsPixels()
msen := minSizeEffective(createLayoutItemForWidget(next))
dpi := s.draggedHandle.DPI()
handleWidth := IntFrom96DPI(s.handleWidth, dpi)
if s.Orientation() == Horizontal {
xh := s.draggedHandle.XPixels()
xnew := xh + x - s.mouseDownPos.X
if xnew < bp.X+msep.Width {
xnew = bp.X + msep.Width
} else if xnew >= bn.X+bn.Width-msen.Width-handleWidth {
xnew = bn.X + bn.Width - msen.Width - handleWidth
}
if e := s.draggedHandle.SetXPixels(xnew); e != nil {
return
}
} else {
yh := s.draggedHandle.YPixels()
ynew := yh + y - s.mouseDownPos.Y
if ynew < bp.Y+msep.Height {
ynew = bp.Y + msep.Height
} else if ynew >= bn.Y+bn.Height-msen.Height-handleWidth {
ynew = bn.Y + bn.Height - msen.Height - handleWidth
}
if e := s.draggedHandle.SetYPixels(ynew); e != nil {
return
}
}
rc := bh.toRECT()
if s.Orientation() == Horizontal {
rc.Left -= int32(bp.X)
rc.Right -= int32(bp.X)
} else {
rc.Top -= int32(bp.Y)
rc.Bottom -= int32(bp.Y)
}
win.InvalidateRect(prev.Handle(), &rc, true)
rc = bh.toRECT()
if s.Orientation() == Horizontal {
rc.Left -= int32(bn.X)
rc.Right -= int32(bn.X)
} else {
rc.Top -= int32(bn.Y)
rc.Bottom -= int32(bn.Y)
}
win.InvalidateRect(next.Handle(), &rc, true)
s.draggedHandle.Invalidate()
})
handle.MouseUp().Attach(func(x, y int, button MouseButton) {
if s.draggedHandle == nil {
return
}
defer s.RequestLayout()
dragHandle := s.draggedHandle
handleIndex := s.children.Index(dragHandle)
prev := closestVisibleWidget(handleIndex, -1)
next := closestVisibleWidget(handleIndex, 1)
s.draggedHandle = nil
dragHandle.SetBackground(NullBrush())
prev.AsWidgetBase().invalidateBorderInParent()
next.AsWidgetBase().invalidateBorderInParent()
prev.SetSuspended(true)
defer prev.Invalidate()
defer prev.SetSuspended(false)
next.SetSuspended(true)
defer next.Invalidate()
defer next.SetSuspended(false)
bh := dragHandle.BoundsPixels()
bp := prev.BoundsPixels()
bn := next.BoundsPixels()
var sizePrev int
var sizeNext int
if s.Orientation() == Horizontal {
bp.Width = bh.X - bp.X
bn.Width -= (bh.X + bh.Width) - bn.X
bn.X = bh.X + bh.Width
sizePrev = bp.Width
sizeNext = bn.Width
} else {
bp.Height = bh.Y - bp.Y
bn.Height -= (bh.Y + bh.Height) - bn.Y
bn.Y = bh.Y + bh.Height
sizePrev = bp.Height
sizeNext = bn.Height
}
layout := s.Layout().(*splitterLayout)
prevItem := layout.hwnd2Item[prev.Handle()]
prevItem.size = sizePrev
prevItem.oldExplicitSize = sizePrev
nextItem := layout.hwnd2Item[next.Handle()]
nextItem.size = sizeNext
nextItem.oldExplicitSize = sizeNext
})
}
}()
}
}
return s.ContainerBase.onInsertedWidget(index, widget)
}
func (s *Splitter) onRemovingWidget(index int, widget Widget) (err error) {
return s.ContainerBase.onRemovingWidget(index, widget)
}
func (s *Splitter) onRemovedWidget(index int, widget Widget) (err error) {
defer func() {
if err != nil {
return
}
s.updateMarginsForFocusEffect()
}()
_, isHandle := widget.(*splitterHandle)
if !s.removing && isHandle && s.children.Len()%2 == 1 {
return newError("cannot remove splitter handle")
}
if !isHandle {
sl := s.layout.(*splitterLayout)
widget.AsWidgetBase().Property("Visible").Changed().Detach(sl.hwnd2Item[widget.Handle()].visibleChangedHandle)
}
if !isHandle && s.children.Len() > 1 {
defer func() {
if err != nil {
return
}
var handleIndex int
if index == 0 {
handleIndex = 0
} else {
handleIndex = index - 1
}
s.removing = true
handle := s.children.items[handleIndex].window.(*splitterHandle)
if err = handle.SetParent(nil); err == nil {
sl := s.layout.(*splitterLayout)
for _, item := range sl.hwnd2Item {
item.oldExplicitSize = 0
item.keepSize = false
}
sl.resetNeeded = true
s.RequestLayout()
handle.Dispose()
}
s.removing = false
}()
}
err = s.ContainerBase.onRemovedWidget(index, widget)
return
}
func (s *Splitter) onClearingWidgets() (err error) {
panic("not implemented")
}
func (s *Splitter) onClearedWidgets() (err error) {
panic("not implemented")
}
func (s *Splitter) CreateLayoutItem(ctx *LayoutContext) LayoutItem {
return s.layout.CreateLayoutItem(ctx)
}