My AppDesigner (R2022a) has a model on the plot; I need to be able to click *anywhere* in the model/plot and store the coordinates of the click.

My app automatically inports the model and adds it to the plot, along with the default boundary lines to plot. I need to be able to click on the plot (or model) and store the coordinates of that click, later those coordinates will be used to update the boundary lines.

function startupFcn(app)
    load('TIMagneticModels.ti','bounds','data','model','topo','-mat')
    app.magData.bounds=bounds;
    app.magData.data=data;
    app.magData.model=model;
    app.magData.topo=topo;
    app.Sb.Value=round(min(app.magData.bounds.ycut)-500);
    app.Nb.Value=round(max(bounds.ycut)+500);
    app.Eb.Value=round(max(bounds.xcut)+500);
    app.Wb.Value=round(min(bounds.xcut)-500);
    UpdateBounds(app);
    GridSize(app);
    plotTMIBounds(app);
end

function ModelButtonDown(app, event) % Button Down function of app.Model
	clickedPoint = get(app.Model, 'CurrentPoint');
	xCoord = clickedPoint(1,1)
	yCoord = clickedPoint(1,2)
	app.Nb.Value = xCoord
	app.Wb.Value = yCoord
end

function ModelPaneButtonDown(app, event) % Button Down function of app.ModelPane
	clickedPoint = get(app.Model, 'CurrentPoint');
	xCoord = clickedPoint(1,1)
	yCoord = clickedPoint(1,2)
	app.Nb.Value = xCoord
	app.Wb.Value = yCoord
end

This code works only to store the coordinates if they are not on the model. Clicking on the model saves nothing.

[VBBV]

Can you check whether the ModelButtonDown and ModelPaneButtonDown components are grouped in the design view ?

[Brandy Barker]

Do you mean this?

Or that when I select app.ModelPane it also automatically shows the edges of app.Model?

[VBBV]

Yes, the latter one. It seems they are both grouped together. Can you ungroup them and try again whether it records the coordinates of the clicked point on the model now ? It also appears (from former snapshot) that model is child of modelpane component.

[Brandy Barker]

I wasn't sure how to ungroup them, so I just deleted the panel. It still reocgnizes and stores the coordinates when I click in the white space above/below the model, but not on the model itself (red box).

Answer 1

[Yatharth]

Hi,

I understand that you are trying to store the x and y coordinate when clicking on the plot inside the App Designer

To implement the functionality of clicking on the plot or model in App Designer and storing the coordinates of the click, you can follow these steps:

1. Open App Designer in MATLAB.
2. Add a UIAxes component to your app's user interface. This will be the plot where you want to capture the click coordinates.
3. In the "Properties" section of the UIAxes component, set the 'ButtonDownFcn' property to UIAxesButtonDown. This property allows you to specify the callback function that will be triggered when a mouse button is clicked on the plot.
4. In the "Code View" section of App Designer, add the following code:

methods (Access = private)

        % Button down function: UIAxes
        function UIAxesButtonDown(app, event)
            clickCoords = get(app.UIAxes, 'CurrentPoint');
            x = clickCoords(1,1);
            y = clickCoords(1,2);
    
            % Store the click coordinates in app variables
            app.clickedX = x;
            app.clickedY = y;

            % Call a function to update the boundary lines using the stored coordinates
            updateBoundaryLines(app);
        end
end 

5. Make sure to define clickedX and clickedY explicitly in app's class definition to access them

properties (Access = private)
    clickedX double
    clickedY double
end

6. Now you can define your updateBoundaryLines function which is being called inside UIAxesButtonDown function

methods (Access = private) 
    function updateBoundaryLines(app)
        coordinatesText = sprintf('Clicked at (%.2f, %.2f)', app.clickedX , app.clickedY);
        disp(coordinatesText);
    end
end

you can learn more about UIAxes from this link.