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// 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 (
"math"
"strconv"
"github.com/lxn/win"
)
type ImageViewMode int
const (
ImageViewModeIdeal ImageViewMode = iota
ImageViewModeCorner
ImageViewModeCenter
ImageViewModeShrink
ImageViewModeZoom
ImageViewModeStretch
)
type ImageView struct {
*CustomWidget
image Image
imageChangedPublisher EventPublisher
margin int
marginChangedPublisher EventPublisher
mode ImageViewMode
}
func NewImageView(parent Container) (*ImageView, error) {
iv := new(ImageView)
cw, err := NewCustomWidget(parent, 0, func(canvas *Canvas, updateBounds Rectangle) error {
return iv.drawImage(canvas, updateBounds)
})
if err != nil {
return nil, err
}
iv.CustomWidget = cw
if err := InitWrapperWindow(iv); err != nil {
iv.Dispose()
return nil, err
}
iv.SetInvalidatesOnResize(true)
iv.SetBackground(NullBrush())
iv.MustRegisterProperty("Image", NewProperty(
func() interface{} {
return iv.Image()
},
func(v interface{}) error {
var img Image
switch val := v.(type) {
case Image:
img = val
case int:
var err error
if img, err = Resources.Image(strconv.Itoa(val)); err != nil {
return err
}
case string:
var err error
if img, err = Resources.Image(val); err != nil {
return err
}
default:
return ErrInvalidType
}
return iv.SetImage(img)
},
iv.imageChangedPublisher.Event()))
iv.MustRegisterProperty("Margin", NewProperty(
func() interface{} {
return iv.Margin()
},
func(v interface{}) error {
return iv.SetMargin(assertIntOr(v, 0))
},
iv.MarginChanged()))
return iv, nil
}
func (iv *ImageView) LayoutFlags() LayoutFlags {
if iv.mode == ImageViewModeIdeal {
return 0
}
return iv.CustomWidget.LayoutFlags()
}
func (iv *ImageView) MinSizeHint() Size {
if iv.mode == ImageViewModeIdeal {
return iv.SizeHint()
}
return Size{iv.margin*2 + 1, iv.margin*2 + 1}
}
func (iv *ImageView) SizeHint() Size {
if iv.mode == ImageViewModeIdeal && iv.image != nil {
s := iv.image.Size()
s.Width += iv.margin * 2
s.Height += iv.margin * 2
return s
}
return iv.CustomWidget.SizeHint()
}
func (iv *ImageView) Mode() ImageViewMode {
return iv.mode
}
func (iv *ImageView) SetMode(mode ImageViewMode) {
if mode == iv.mode {
return
}
iv.mode = mode
iv.Invalidate()
iv.updateParentLayout()
}
func (iv *ImageView) Image() Image {
return iv.image
}
func (iv *ImageView) SetImage(value Image) error {
if value == iv.image {
return nil
}
iv.image = value
_, isMetafile := value.(*Metafile)
iv.SetClearsBackground(isMetafile)
err := iv.Invalidate()
if iv.mode == ImageViewModeIdeal {
iv.updateParentLayout()
}
iv.imageChangedPublisher.Publish()
return err
}
func (iv *ImageView) ImageChanged() *Event {
return iv.imageChangedPublisher.Event()
}
func (iv *ImageView) Margin() int {
return iv.margin
}
func (iv *ImageView) SetMargin(margin int) error {
if margin == iv.margin {
return nil
}
iv.margin = margin
err := iv.Invalidate()
iv.marginChangedPublisher.Publish()
return err
}
func (iv *ImageView) MarginChanged() *Event {
return iv.marginChangedPublisher.Event()
}
func (iv *ImageView) drawImage(canvas *Canvas, updateBounds Rectangle) error {
if iv.image == nil {
return nil
}
cb := iv.ClientBoundsPixels()
cb.Width -= iv.margin * 2
cb.Height -= iv.margin * 2
s := iv.image.Size()
switch iv.mode {
case ImageViewModeShrink, ImageViewModeZoom, ImageViewModeStretch:
var bounds Rectangle
if iv.mode == ImageViewModeStretch {
bounds.X = iv.margin
bounds.Y = iv.margin
bounds.Width = cb.Width
bounds.Height = cb.Height
} else {
var scale float64
if iv.mode == ImageViewModeZoom || s.Width > cb.Width || s.Height > cb.Height {
sx := float64(cb.Width) / float64(s.Width)
sy := float64(cb.Height) / float64(s.Height)
scale = math.Min(sx, sy)
} else {
scale = 1.0
}
bounds.Width = int(float64(s.Width) * scale)
bounds.Height = int(float64(s.Height) * scale)
bounds.X = iv.margin + (cb.Width-bounds.Width)/2
bounds.Y = iv.margin + (cb.Height-bounds.Height)/2
}
return canvas.DrawImageStretched(iv.image, bounds)
case ImageViewModeCorner, ImageViewModeCenter:
win.IntersectClipRect(canvas.hdc, int32(iv.margin), int32(iv.margin), int32(cb.Width+iv.margin), int32(cb.Height+iv.margin))
}
var pos Point
switch iv.mode {
case ImageViewModeIdeal, ImageViewModeCorner:
pos.X = iv.margin
pos.Y = iv.margin
case ImageViewModeCenter:
pos.X = iv.margin + (cb.Width-s.Width)/2
pos.Y = iv.margin + (cb.Height-s.Height)/2
}
return canvas.DrawImage(iv.image, pos)
}
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