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

123 lines
2.5 KiB
Go

// Copyright 2018 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 (
"sync"
)
type TextLabel struct {
static
textChangedPublisher EventPublisher
}
func NewTextLabel(parent Container) (*TextLabel, error) {
return NewTextLabelWithStyle(parent, 0)
}
func NewTextLabelWithStyle(parent Container, style uint32) (*TextLabel, error) {
tl := new(TextLabel)
if err := tl.init(tl, parent); err != nil {
return nil, err
}
tl.textAlignment = AlignHNearVNear
tl.MustRegisterProperty("Text", NewProperty(
func() interface{} {
return tl.Text()
},
func(v interface{}) error {
return tl.SetText(assertStringOr(v, ""))
},
tl.textChangedPublisher.Event()))
return tl, nil
}
func (tl *TextLabel) asStatic() *static {
return &tl.static
}
func (tl *TextLabel) TextAlignment() Alignment2D {
return tl.textAlignment
}
func (tl *TextLabel) SetTextAlignment(alignment Alignment2D) error {
if alignment == AlignHVDefault {
alignment = AlignHNearVNear
}
return tl.setTextAlignment(alignment)
}
func (tl *TextLabel) Text() string {
return tl.text()
}
func (tl *TextLabel) SetText(text string) error {
if changed, err := tl.setText(text); err != nil {
return err
} else if !changed {
return nil
}
tl.textChangedPublisher.Publish()
return nil
}
func (tl *TextLabel) CreateLayoutItem(ctx *LayoutContext) LayoutItem {
return &textLabelLayoutItem{
width2Height: make(map[int]int),
text: tl.Text(),
font: tl.Font(),
minWidth: tl.MinSizePixels().Width,
}
}
type textLabelLayoutItem struct {
LayoutItemBase
mutex sync.Mutex
width2Height map[int]int // in native pixels
text string
font *Font
minWidth int // in native pixels
}
func (*textLabelLayoutItem) LayoutFlags() LayoutFlags {
return GrowableHorz | GrowableVert
}
func (li *textLabelLayoutItem) IdealSize() Size {
return li.MinSize()
}
func (li *textLabelLayoutItem) MinSize() Size {
return calculateTextSize(li.text, li.font, li.ctx.dpi, li.minWidth, li.handle)
}
func (li *textLabelLayoutItem) HasHeightForWidth() bool {
return true
}
func (li *textLabelLayoutItem) HeightForWidth(width int) int {
li.mutex.Lock()
defer li.mutex.Unlock()
if height, ok := li.width2Height[width]; ok {
return height
}
size := calculateTextSize(li.text, li.font, li.ctx.dpi, width, li.handle)
li.width2Height[width] = size.Height
return size.Height
}