Android Question draw arc Transparent

[park jae hyun]

Sub DrawCircleArc(cx As Float, cy As Float, Radius As Float, StartAngle As Float, SweepAngle As Float, col As Int, Filled As Boolean, StrokeWidth As Float, UseCenter As Boolean)
Dim r As ABRectF
r.Initialize(cx - Radius, cy - Radius, cx + Radius, cy + Radius)
Dim paint As ABPaint
paint.Initialize
If Filled = True Then
paint.SetStyle(paint.Style_FILL)
Else
paint.SetStyle(paint.Style_STROKE)
End If

paint.SetColor(col)

paint.SetStrokeWidth(StrokeWidth)
ExtDrawing.drawArc(cvsMain, r, StartAngle, SweepAngle, UseCenter, paint)
End Sub



Sub button1_click
DrawCircleArc(300, 600, 320, 25, 20, Colors.Transparent , False, 6, True)
End Sub


Sub button2_click
DrawCircleArc(300, 600, 320, 25, 20, Colors.Green, False, 6, True)
End Sub

question
Not transparent.

 

[Erel]

Please use [code]code here...[/code] tags when posting code.

 

[park jae hyun]

Sub DrawCircleArc(cx As Float, cy As Float, Radius As Float, StartAngle As Float, SweepAngle As Float, col As Int, Filled As Boolean, StrokeWidth As Float, UseCenter As Boolean)
Dim r As ABRectF
r.Initialize(cx - Radius, cy - Radius, cx + Radius, cy + Radius) 
Dim paint As ABPaint
paint.Initialize
If Filled = True Then
paint.SetStyle(paint.Style_FILL)
Else
paint.SetStyle(paint.Style_STROKE)
End If

paint.SetColor(col) 

paint.SetStrokeWidth(StrokeWidth)
ExtDrawing.drawArc(cvsMain, r, StartAngle, SweepAngle, UseCenter, paint)
End Sub



Sub button1_click
DrawCircleArc(300, 600, 320, 25, 20, Colors.Transparent , False, 6, True) 
End Sub


Sub button2_click
DrawCircleArc(300, 600, 320, 25, 20, Colors.Green, False, 6, True)
End Sub

question
Not transparent.

 

[Erel]

It is very simple to draw arcs with XUI library.

Create a B4XPath initialized with InitializeArc and draw it with B4XCanvas.DrawPath.

Sub Activity_Create(FirstTime As Boolean)
   Dim c As B4XCanvas
   c.Initialize(Activity)
   Dim p As B4XPath
   p.InitializeArc(50%x, 50%y, 100dip, 0, 135)
   c.DrawPath(p, 0xffff0000, True, 0)
   p.InitializeArc(50%x, 50%y, 100dip, 90, 135)
   c.DrawPath(p, 0x8800ff00, True, 0)
   c.Invalidate
   c.Release
End Sub

 

[park jae hyun]

Thank you for answer.
But I think I got the wrong question.

I want to clear a specific part.

 

[klaus]

It works with the 'standard' Canvas.
You can use DrawRect, DrawCircle or DrawOval.
I haven't tested with DrawPath.
With ABExtDrawing, transparent color doesn't set the background to transparent but draw a transparent color which means does nothing..

 

[Erel]

Simple:

Dim c As B4XCanvas
c.Initialize(Activity)
Dim p As B4XPath
p.InitializeArc(50%x, 50%y, 100dip, 0, 135)
c.DrawPath(p, 0xffff0000, True, 0)
p.InitializeArc(55%x, 55%y, 40dip, 0, 135)
c.ClipPath(p)
c.ClearRect(c.TargetRect)
c.RemoveClip
c.Invalidate
c.Release

Unlike the previous code that will work in B4A, B4i and B4J, this code will only work in B4A and B4i as ClearRect in B4J ignores the clipped region.

 

[park jae hyun]

klaus , Erel
Thank you very much.
Thank you very much.