MATLAB: Accessing the annotation handle

annotation;plot

Hi, I am creating a 2d plot and inserting a textarrow using the figure window 'drop down' menu options. Later I wanted to access the handle of the textarrow thus created, so that I can get the positions, strings etc related to the textarrow. So my question is how can access the textarrow handle (the textarrow being created MANUALLY through gui options. Thanks Samik

Best Answer

Samik - it seems that annotation objects (like the one that you have describe above) are children of a hidden axes named scribeOverlay. So you can try using the findall command to find this axes, and so the child annotation object. In R2014a, I created a figure and (like you) added a text arrow via the menu. In the Command Window (or your script or function), type

 % get the handle of the hidden annotation axes
 hAnnotAxes = findall(gcf,'Tag','scribeOverlay');
 % get its children handles
 if ~isempty(hAnnotAxes)
     hAnnotChildren = get(hAnnotAxes,'Children');
     % do something with the annotation handles...
 end

Try the above and see what happens!

Related Solutions

MATLAB: How to find the handle of a figure object, which was inserted by using the figure menu in MATLAB 7.4 (R2007a)

The objects in a figure which were inserted by using the figure's 'Insert' menu are created in an additional invisible axes and their handles are hidden by default. You can disable handle hiding by setting "ShowHiddenHandles" property to 'on' and using FINDOBJ function as in the following example code:

% Show all figure’s hidden handles.
set(0,'showhiddenhandles','on')
% Obtain the handle for line using its 'Type' property
h = findobj(gcf,'Type','hggroup');

MATLAB: How to get the properties of annotation objects in the current figure

To obtain the properties and values of annotation objects in the current figure, search the figure using the FINDALL function to locate hggroup objects that are children of the annotation object parent axes. The following code provides an example:

close all
clear all
% Create some annotations
annotation('textbox',[0.5 0.5 0.1 0.1],'string','hello world');
annotation('textbox',[0.7 0.9 0.1 0.1],'string','hello world1');
annotation('textbox',[0.2 0.2 0.1 0.1],'string','hello world2');
annotation('line',[0.2 0.2],[0.8 0.3]);
fig = gcf;
% Return the axes that contains the annotation objects
ax = findall(fig, 'Type', 'axes', 'Tag', 'scribeOverlay');
% Find the Children with type hggroup
annotation_handles = findall(get(ax,'Children'),'Type','hggroup');
ss = size(annotation_handles);
j = max(ss);
% In a loop, determine if the annotations are of textbox type
for i = 1:j
     hh = get(annotation_handles(i));
     % Check if the object has a 'String' property
     if(isfield(hh,'String'))
     text_string{i} = get(annotation_handles(i),'string');
     else i = i+1;
     end
end
% Display the strings in the annotation textboxes
text_string

It is important to note that all annotation objects are of type 'hggroup' and hence based on the type you cannot determine whether it is a textbox or a line. Hence, you will need to find if the 'String' property exists in the handle structure of the annotation object.

Best Answer

Related Solutions

MATLAB: How to find the handle of a figure object, which was inserted by using the figure menu in MATLAB 7.4 (R2007a)

MATLAB: How to get the properties of annotation objects in the current figure

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