WindowButtonMotionFcn cannot be changed in later time

Hi, I am creating a figure and customize the pan-function:

function hFig = mouse_figure
...
hFig  = figure;
set(hFig,...
    'WindowButtonDownFcn'  , @pan_click,...
    'WindowButtonUpFcn'    , @pan_release,...
    'WindowButtonMotionFcn', @pan_motion);
...
end

Then in the caller workspace, I need to update the WindowButtonMotionFcn to a new function that incorporate more arguments and do more stuffs. However, after the figure was shown, I found that the WindowButtonMotionFcn was not called as expected. Instead, it is still calling the original pan_motion. Is there something wrong with the code?

function f = test
    f  = mouse_figure;

    % debug here, get that:
    %   WindowButtonDownFcn: @mouse_figure/pan_click
    % WindowButtonMotionFcn: @mouse_figure/pan_motion
    %     WindowButtonUpFcn: @mouse_figure/pan_release
    
plot([1,2],[3,4])
zoom yon
    % debug here, get that:
    %     WindowButtonDownFcn: {3x1 cell}
    %     WindowButtonMotionFcn: @mouse_figure/pan_motion
    %     WindowButtonUpFcn: {3x1 cell}
    
    % f.WindowButtonDownFcn
    % ans = 
    %     @localModeWindowButtonDownFcn                    
    %     [1x1 matlab.uitools.internal.uimode]
    %     @(obj,evd)localWindowButtonDownFcn(obj,evd,hMode)
     
    %  f.WindowButtonUpFcn
    % ans = 
    %     @localModeWindowButtonUpFcn         
    %     [1x1 matlab.uitools.internal.uimode]
    %     []
    
set(f,'WindowButtonMotionFcn', @(~,~) pan_motion_driftPatchTextObjs(f,panHor,panVer,aYTopTextPatchCollects,aXLeftTextPatchCollects));

    % debug here, get that:
    
        % WindowButtonDownFcn: {3x1 cell}
        % WindowButtonMotionFcn: [function_handle]
        % WindowButtonUpFcn: {3x1 cell}
        
        % f.WindowButtonDownFcn
        % ans = 
        %     @localModeWindowButtonDownFcn                    
        %     [1x1 matlab.uitools.internal.uimode]
        %     @(obj,evd)localWindowButtonDownFcn(obj,evd,hMode)
        
        % f.WindowButtonMotionFcn
        % ans = 
        %     @(~,~)pan_motion_driftPatchTextObjs(f,panHor,panVer,aYTopTextPatchCollects,aXLeftTextPatchCollects)
        
        %  f.WindowButtonUpFcn
        % ans = 
        %     @localModeWindowButtonUpFcn         
        %     [1x1 matlab.uitools.internal.uimode]
        %     []
end

% after exit to base workspace:
a = ans;
a

        % WindowButtonDownFcn: {3x1 cell}
        % WindowButtonMotionFcn: @mouse_figure/pan_motion
        % WindowButtonUpFcn: {3x1 cell}
        
        % a.WindowButtonDownFcn
        % ans = 
        %     @localModeWindowButtonDownFcn                  
        %     [1x1 matlab.uitools.internal.uimode]
        %     @(obj,evd)locWindowButtonDownFcn(obj,evd,hMode)
         
        % a.WindowButtonMotionFcn
        % ans = 
        %     @mouse_figure/pan_motion
         
        % a.WindowButtonUpFcn
        % ans = 
        %     @localModeWindowButtonUpFcn         
        %     [1x1 matlab.uitools.internal.uimode]
        %     []

Answer 1

[raym]

I found the reason:

zoom yon

this command modifies the pan callbacks into an temporary status, thus modification of pan callback when zoom is on is not stable.

After remove the command, it is OK now.