MATLAB: Is it possible to change the color of the cursor when using the GINPUT function

axescolorcoordinatesgetginputMATLAB

I am trying to change the color of the cursor when using the "ginput" function and am unable to do so.

Best Answer

The ability to change the color of the cursor to something other than black or white when using the "ginput" function is not available in MATLAB.

As a workaround, you can use the "WindowButtonMotionFcn" together with the "WindowButtonDownFcn" to replicate the functionality of the "ginput" function while adding the ability to change the color of the cursor.

Attached is an example MATLAB code that illustrates how to do this.

Another solution using the "WindowButtonMotionFcn" together with "WindowButtonDownFcn" can be found on MathWorks File Exchange.

https://www.mathworks.com/matlabcentral/fileexchange/38703-custom-ginput

For questions regarding this File Exchange function, please contact the author of the post directly.

Related Solutions

MATLAB: How to override the zoom uicontextmenu with a custom uicontextmenu, when in zoom mode, in MATLAB 7.3 (R2006b)

This can be accomplished with the zoom accessor object. The following example illustartes how this can be done:

% Define the context menu
cmenu = uicontextmenu;
% Define the line and associate it with the context menu
hline = plot(1:10,'UIContextMenu', cmenu);
% Define callbacks for context menu items
cb1 = ['set(hline, ''LineStyle'', ''--'')'];
cb2 = ['set(hline, ''LineStyle'', '':'')'];
cb3 = ['set(hline, ''LineStyle'', ''-'')'];
% Define the context menu items
item1 = uimenu(cmenu, 'Label', 'dashed', 'Callback', cb1);
item2 = uimenu(cmenu, 'Label', 'dotted', 'Callback', cb2);
item3 = uimenu(cmenu, 'Label', 'solid', 'Callback', cb3);
% Get the handle to the zoom mode object for the figure
zh = zoom(gcf);
% Set the UI Context Menu to the custom menu
set(zh, 'uicontextmenu', cmenu)

MATLAB: How to continuously track / record coordinates of the cursor over an axes in the figure window

To continuously track/record the position of the user's cursor, set up a "WindowButtonMotionFcn" callback for your figure:

https://www.mathworks.com/help/matlab/ref/matlab.ui.figure-properties.html#buiwuyk-1-WindowButtonMotionFcn

This callback will be triggered any time the cursor moves. Set the callback as a function handle pointing to a function that gets the "CurrentPosition" of the axes and displays these coordinates in the textbox:

https://www.mathworks.com/help/matlab/ref/matlab.graphics.axis.axes-properties.html#budumk7-CurrentPoint

To stop tracking the cursor, set up a "WindowButtonDownFcn" callback for your figure:

https://www.mathworks.com/help/matlab/ref/matlab.ui.figure-properties.html#buiwuyk-1-WindowButtonDownFcn

This callback will be triggered any time the user left-clicks inside the figure window. Set the callback as a function handle pointing to a function that sets the "WindowButtonMotionFcn" property to an empty string. This will prevent the tracking/recording function from being called when the mouse moves.

Below is an example, putting all these ideas together. Again, a callback is triggered whenever the user moves their mouse in the figure, and the mouse coordinates are displayed in the textbox. The recording of these coordinates will permanently stop when the user left-clicks on the

mouse and thus triggers the "WindowButtonDown" callback.

% Create figure with axes and textbox
f = figure;
ax = axes(f,'Units','normalized','Position',[.1 .3 .8 .6]);
txt = annotation(f,'textbox','FontSize',12,...
         'Units','normalized','Position',[.1 .1 .35 .06],...
         'BackgroundColor','white');
% set up callbacks for figure
f.WindowButtonMotionFcn = {@mouseMove,ax,txt};
f.WindowButtonDownFcn = @stopTracking;
% define callback functions
function mouseMove(~,~,ax,txt)
    % get x and y position of cursor
    xPos = ax.CurrentPoint(1,1);
    yPos = ax.CurrentPoint(1,2);
      % display coordinates in textbox
      txt.String = "x: "+xPos+" y: "+yPos;
  end
function stopTracking(f,~)
    % stop callback to mouseMove
    f.WindowButtonMotionFcn = "";
end

If you are unfamiliar with callbacks, here is a basic introduction to using callback functions in MATLAB:

https://www.mathworks.com/help/matlab/creating_plots/callbacks-programmed-response-to-user-action.html

And here are some other callbacks for figure windows:

https://www.mathworks.com/help/matlab/ref/matlab.ui.figure-properties.html#d117e400687

Best Answer

Related Solutions

MATLAB: How to override the zoom uicontextmenu with a custom uicontextmenu, when in zoom mode, in MATLAB 7.3 (R2006b)

MATLAB: How to continuously track / record coordinates of the cursor over an axes in the figure window

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