Why findobj cannot find a TexBox (annotation) object?

While HandleVisibility property of a TextBox object is 'on' by default,

fig = figure
txb = annotation('textbox',[0.5 0.5 0.5 0.5],'String','bar hoo')

class(txb)

ans =

'matlab.graphics.shape.TextBox'

txb.Type % 

ans = 'textboxshape'

txb.HandleVisibility

ans = 'on'

findobj cannot find this txb.

findobj(fig,'Type','textboxshape')

ans =

0×0 empty GraphicsPlaceholder array.

Why is this and how can I find this txb?

Answer 1

[Cris LaPierre]

Try using the object handle (txb) directly.

plot(1:10)
str = 'Straight Line Plot from 1 to 10';
txb = annotation('textbox',[.2 .5 .3 .3],'String',str,'FitBoxToText','on');

●

% Use object handle
findobj(txb)

ans = 
  TextBox (Straight Line Plot from 1 to 10) with properties:

             String: 'Straight Line Plot from 1 to 10'
           FontName: 'Helvetica'
           FontSize: 10
         FontWeight: 'normal'
              Color: [0 0 0]
    BackgroundColor: 'none'
          EdgeColor: [0 0 0]
          LineStyle: '-'
          LineWidth: 0.5000
           Position: [0.2000 0.5000 0.3000 0.3000]
              Units: 'normalized'

  Show all properties

If you want to instead find the annotation without using the object handle, use findall instead.

findall(gcf,'Type','textboxshape')

ans = 
  TextBox (Straight Line Plot from 1 to 10) with properties:

             String: 'Straight Line Plot from 1 to 10'
           FontName: 'Helvetica'
           FontSize: 10
         FontWeight: 'normal'
              Color: [0 0 0]
    BackgroundColor: 'none'
          EdgeColor: [0 0 0]
          LineStyle: '-'
          LineWidth: 0.5000
           Position: [0.2000 0.5000 0.3000 0.3000]
              Units: 'normalized'

  Show all properties

[Kouichi C. Nakamura]

Uh-huh, I totally missed the existence of findall, the very function for my case. Thanks!

[Kouichi C. Nakamura]

Besides, the ducumentation of findobj doesn't really say you cannot use a figure object as the first input argument of fingobj, does it?

In one of the examples, gcf is used with fingobj:

h2 = findobj(gcf,'-depth',2)

[Cris LaPierre]

Good point. The underlying issue was handle visibility, as you pointed out below. I'll update my response to remove any confusion.

[Kouichi C. Nakamura]

Thanks!

Answer 2

[Kouichi C. Nakamura]

It turned out that TextBox txb is a child of an AnnotationPane or 'matlab.graphics.shape.internal.AnnotationPane' object. And HandleVisibility of AnnotationPane objects are 'off' by default, hiding the handle of TextBox txb.

So you need to set HandleVisibility of AnnotationPane objects to 'on' first, and then use findobj.

set(findobj(allchild(fig),'Type','AnnotationPane'),...
    'HandleVisibility','on') 

findobj(fig,'Type','textboxshape') % WORKS!

ans =

TextBox (bar hoo) with properties:

String: 'bar hoo'

FontName: 'Helvetica'

FontSize: 10

FontWeight: 'normal'

Color: [0 0 0]

BackgroundColor: 'none'

EdgeColor: [0 0 0]

LineStyle: '-'

LineWidth: 0.5000

Position: [0.5000 0.5000 0.5000 0.5000]

Units: 'normalized'

Show all properties