Is there any way to draw a line with arrow in wx?

[Shannon]

Hi, 

I was wondering is there any way to draw a line with an arrow, which can indicate the from 'point 1' point to 'point 2'.

Does anyone know how to implement this?

Thanks

Shannon

[Vlastimil Brom]

2013/2/21 Shannon <shanno...@gmail.com>:

> --
> You received this message because you are subscribed to the Google Groups
> "wxPython-users" group.
> To unsubscribe from this group and stop receiving emails from it, send an
> email to wxpython-user...@googlegroups.com.
> For more options, visit https://groups.google.com/groups/opt_out.
>
>

Hi,
I haven't used any of these myself, but OGL and FloatCanvas come to
mind in this context; see the wxpython demo:
More windows/controls: FloatCanvas
Miscelaneous: OGL

There are likely some other graphic libraris, with this capabilitry.

hth,
vbr

[Bruce Sherwood]

Probably overkill, but VPython (vpython.org), which is now based on wxPython, makes it extremely easy to draw a 3D arrow. The single statement

arrow()

draws a default white arrow with its tail at the origin, pointing to the right, with length 1. You can optionally specify a tail position, a direction and length, and a color:

A = arrow(pos=(1,2,-1), axis(5,2,3), color=color.cyan)

Later in the program you can alter any of these attributes. For example,

A.color = color.red

With the mouse you can zoom and rotate the "camera" that is viewing the 3D scene.

[Chris Barker - NOAA Federal]

On Thu, Feb 21, 2013 at 1:21 PM, Vlastimil Brom
<vlastim...@gmail.com> wrote:
> 2013/2/21 Shannon <shanno...@gmail.com>:

>> I was wondering is there any way to draw a line with an arrow, which can
>> indicate the from 'point 1' point to 'point 2'.

> I haven't used any of these myself, but OGL and FloatCanvas come to
> mind in this context; see the wxpython demo:
> More windows/controls: FloatCanvas

Indeed -- for FloatCanvas, look at the main Demo, look at the "Arrows"
demo under the "Tests" Menu - the arrows are not particularly pretty,
but you could make your own DrawObject with prettier ones if you want.

There are also bunch more little FloatCanvas demos in SVN also:

http://svn.wxwidgets.org/svn/wx/wxPython/3rdParty/FloatCanvas/Demos/

The VectPlot.py demo uses arrows.

-Chris


--

Christopher Barker, Ph.D.
Oceanographer

Emergency Response Division
NOAA/NOS/OR&R (206) 526-6959 voice
7600 Sand Point Way NE (206) 526-6329 fax
Seattle, WA 98115 (206) 526-6317 main reception

Chris....@noaa.gov

[Edward Sitarski]

I realize this question was asked a long time ago.

Sometimes you simply want to draw an arrow in a dc.

I recently ran into this problem.  See below:

from math import atan2, sin, cos, pi

def DrawArrowLine( dc, x0, y0, x1, y1, arrowFrom=True, arrowTo=True, arrowLength=16, arrowWidth=8 ):

    '''

        Draws a line with arrows in a regular wxPython DC.

        The line is drawn with the dc's wx.Pen.  The arrows are filled with the current Pen's colour.

        Edward Sitarski 2021.

    '''

    dc.DrawLine( x0, y0, x1, y1 )

    if x0 == x1 and y0 == y1:

        return

    

    # Set up the dc for drawing the arrows.

    penSave, brushSave = dc.GetPen(), dc.GetBrush()

    dc.SetPen( wx.TRANSPARENT_PEN )

    dc.SetBrush( wx.Brush(dc.GetPen().GetColour()) )

    

    # Compute the "to" arrow polygon.

    angle = atan2( y1 - y0, x1 - x0 )

    toCosAngle, toSinAngle = -cos(angle), -sin(angle)

    toArrowPoly = [

        (int(xp*toCosAngle - yp*toSinAngle), int(yp*toCosAngle + xp*toSinAngle)) for xp, yp in (

            (0,0),

            (arrowLength, arrowWidth/2),

            (arrowLength, -arrowWidth/2),

        )

    ]

    

    # Draw the arrows.

    if arrowTo:

        dc.DrawPolygon( toArrowPoly, x1, y1 )

    if arrowFrom:

        dc.DrawPolygon( [(-x,-y) for x,y in toArrowPoly], x0, y0 )

    

    # Restore the dc.

    dc.SetPen( penSave )

    dc.SetBrush( brushSave )

[Edward Sitarski]

Deepest appologies.   The above code has a bug.  Please use the following:

from math import atan2, sin, cos, pi

def DrawArrowLine( dc, x0, y0, x1, y1, arrowFrom=True, arrowTo=True, arrowLength=16, arrowWidth=8 ):

    '''

        Draws a line with arrows in a regular wxPython DC.

        The line is drawn with the dc's wx.Pen.  The arrows are filled with the current Pen's colour.

        Edward Sitarski 2021.

    '''

    dc.DrawLine( x0, y0, x1, y1 )

    if x0 == x1 and y0 == y1:

        return

    

    # Set up the dc for drawing the arrows.

    penSave, brushSave = dc.GetPen(), dc.GetBrush()

    dc.SetPen( wx.TRANSPARENT_PEN )

    dc.SetBrush( wx.Brush(penSave.GetColour()) )

    

    # Compute the "to" arrow polygon.

    angle = atan2( y1 - y0, x1 - x0 )

    toCosAngle, toSinAngle = -cos(angle), -sin(angle)

    toArrowPoly = [

        (int(xp*toCosAngle - yp*toSinAngle), int(yp*toCosAngle + xp*toSinAngle)) for xp, yp in (

            (0,0),

            (arrowLength, arrowWidth/2),

            (arrowLength, -arrowWidth/2),

        )

    ]

    

    # Draw the arrows.

    if arrowTo:

        dc.DrawPolygon( toArrowPoly, x1, y1 )

    if arrowFrom:

        dc.DrawPolygon( [(-x,-y) for x,y in toArrowPoly], x0, y0 )

    

    # Restore the dc.

    dc.SetPen( penSave )

    dc.SetBrush( brushSave )