如何向roImagecanvas添加按钮（customvideoplayer）

Question

我是ROKU开发的新手。如果我的问题看起来很愚蠢，我很抱歉，因为我刚开始使用它。我正在研究ROKU sdk示例附带的 customvideoplayer 示例。我希望在画布上添加按钮，以便播放，停止，最小化和最大化功能。我已经研究过它但是无法添加按钮。此外，我还希望c 确定这些按钮的点击事件，并在点击时执行所需的功能。 如何在按钮单击上编写最大化和最小化代码？

关于如何创建这些按钮并执行所需功能的任何建议都将非常感激。

以下是我正在使用的代码：

Sub RunUserInterface()
o = Setup()
o.setup()
o.paint()
o.eventloop()
End Sub

Sub Setup() As Object
this = {
port: CreateObject("roMessagePort")
progress: 0 'buffering progress
position: 0 'playback position (in seconds)
paused: false 'is the video currently paused?
feedData: invalid
playing: 0
playingPrev: 0
playlistSize: 0
canvas: CreateObject("roImageCanvas") 'user interface
player: CreateObject("roVideoPlayer")
load: LoadFeed
setup: SetupFullscreenCanvas
paint: PaintFullscreenCanvas
create_playlist_text: CreatePlaylistText
drawtext: false
eventloop: EventLoop
}
this.targetRect ={x: 100, y: 100, w: 600, h:500}
' this.targetRect = this.canvas.GetCanvasRect()
'this.textRect = {x: 520, y: 480, w: 300, h:200} 
this.textRect = {x: 150, y: 470, w: 300, h:200} 
this.load()
'Setup image canvas:
this.canvas.SetMessagePort(this.port)
this.canvas.SetLayer(0, { Color: "#000000" })
this.canvas.Show()

this.player.SetMessagePort(this.port)
this.player.SetLoop(true)
this.player.SetPositionNotificationPeriod(1)
this.player.SetDestinationRect(this.targetRect)

this.player.Play()
this.playingPrev = this.playing

return this
End Sub

Sub EventLoop()
while true
msg = wait(0, m.port)
if msg <> invalid
if msg.isStatusMessage() and msg.GetMessage() = "startup progress"
m.paused = false
print "Raw progress: " + stri(msg.GetIndex())
progress% = msg.GetIndex() / 10
if m.progress <> progress%
m.progress = progress%
m.paint()
end if

'Playback progress (in seconds):
else if msg.isPlaybackPosition()
m.position = msg.GetIndex()
print "Playback position: " + stri(m.position)

else if msg.isRemoteKeyPressed()
index = msg.GetIndex()
print "Remote button pressed: " + index.tostr()
if index = 4 '<LEFT>
m.playing = m.playing - 1
if (m.playing < 0)
m.playing = 2
endif
m.player.SetNext(m.playing)
m.player.Play()
m.playingPrev = m.playing
else if index = 8 '<REV>
m.position = m.position - 60
m.player.Seek(m.position * 1000) 
else if index = 5 '<RIGHT>
m.playing = m.playing + 1
if (m.playing > 2)
m.playing = 0
endif
m.player.SetNext(m.playing) 
m.player.Play()
m.playingPrev = m.playing 
else if index = 9 '<REV>
m.position = m.position + 60
m.player.Seek(m.position * 1000)
else if index = 2 '<Up>
if m.drawtext
m.playing = m.playing - 1
if (m.playing < 0)
m.playing = m.playlistSize-1
endif
m.paint()
endif 
else if index = 3 '<Down>
if m.drawtext
m.playing = m.playing + 1
if (m.playing > m.playlistSize-1)
m.playing = 0
endif
m.paint()
endif 
else if index = 13 '<PAUSE/PLAY>
if m.paused m.player.Resume() else m.player.Pause()
else if index = 6 'OK
if m.drawtext
m.drawtext = false  
if m.playing <> m.playingPrev
m.player.SetNext(m.playing) 
m.player.Play()
m.playingPrev = m.playing
endif
else
m.drawtext = true
endif
m.paint()
end if

else if msg.isPaused()
m.paused = true
m.paint()

else if msg.isResumed()
m.paused = false
m.paint()

end if
endif
end while
End Sub

Sub SetupFullscreenCanvas()
m.canvas.AllowUpdates(false)
m.paint()
m.canvas.AllowUpdates(true)
End Sub

Sub PaintFullscreenCanvas()
splash = []
list = []

if m.progress < 100
progress_bar = {TargetRect: {x: 100, y: 500, w: 598, h: 37}, url: "pkg:/images/progress_bar.png"}
color = "#00a0a0a0"
splash.Push({
url: "pkg:/images/splash.png"
TargetRect: m.targetRect
})
list.Push({
Text: "Loading..."
TextAttrs: { font: "large", color: "#707070" }
TargetRect: m.textRect
}) 
if m.progress >= 0 AND m.progress < 20
progress_bar.url = "pkg:/images/progress_bar_1.png"
print progress_bar.url
else if m.progress >= 20 AND m.progress < 40
progress_bar.url = "pkg:/images/progress_bar_2.png"
print progress_bar.url
else if m.progress >= 40 AND m.progress < 75
progress_bar.url = "pkg:/images/progress_bar_3.png"
print progress_bar.url
else
progress_bar.url = "pkg:/images/progress_bar_4.png"
print progress_bar.url 
endif
list.Push(progress_bar)

end if

if m.drawtext
textArr = m.create_playlist_text()
yTxt = 100
color = "#00000000"
index = 0
for each str in textArr
if index = m.playing
textColor = "#00ff00"
else
textColor = "#dddddd"
endif
list.Push({
Text: str
TextAttrs: {color: textColor, font: "medium"}
TargetRect: {x:700, y:yTxt, w: 500, h: 100}
})
yTxt = yTxt + 100
index = index + 1
end for
else
color = "#00000000"
list.Push({
Text: ""
TextAttrs: {font: "medium"}
TargetRect: {x:100, y:600, w: 300, h: 100}
})
endif

'Clear previous contents
m.canvas.ClearLayer(0)
m.canvas.ClearLayer(1)
m.canvas.ClearLayer(2) 
m.canvas.SetLayer(0, { Color: color, CompositionMode: "Source" })
if (splash.Count() > 0)
m.canvas.SetLayer(1, splash)
m.canvas.SetLayer(2, list)
else
m.canvas.SetLayer(1, list)
endif
list.Clear()
splash.Clear()
End Sub

Function LoadFeed() as void
jsonAsString = ReadAsciiFile("pkg:/json/feed.json")
m.feedData = ParseJSON(jsonAsString)
m.playlistSize = m.feedData.Videos.Count()
contentList = []
for each video in m.feedData.Videos
contentList.Push({
Stream: { url: video.url }
StreamFormat: "mp4"
})
end for 
m.player.SetContentList(contentList) 
End Function

Function CreatePlaylistText() as object
textArr = []
for each video in m.feedData.Videos
textArr.Push(video.title)
end for
return textArr
End Function