Minimize and maximize

5.2: Minimize and maximize

When a uiextras.BoxPanel has its "MinimizeFcn" filled in, a minimize/maximize button ( / ) is shown in the upper-right of the title-bar. When the user clicks this button the specified function is called. Since the behaviour of the parent container is different in different use-cases, it is up to the user to write some code to actually resize the panel. Note that minimizing a panel to its title-bar only really makes sense inside a uiextras.VBox or uiextras.VBoxFlex.

The following simple example shows how to add minimize/maximize functionality to a box full of panels. Save the code into a file called "dockexample.m" to run it.

(The code for this example can be found here: [ view | edit | run ] )

Create the layout with three panels

Open a new figure window and add three panels.

function minimizeexample()
width = 200;
pheightmin = 20;
pheightmax = 100;

% Create the window and main layout
fig = figure( 'Name', 'Collapsable GUI example', ...
              'NumberTitle', 'off', ...
              'Toolbar', 'none', ...
              'MenuBar', 'none' );
box = uiextras.VBox( 'Parent', fig );

panel{1} = uiextras.BoxPanel( 'Title', 'Panel 1', 'Parent', box );
panel{2} = uiextras.BoxPanel( 'Title', 'Panel 2', 'Parent', box );
panel{3} = uiextras.BoxPanel( 'Title', 'Panel 3', 'Parent', box );
set( box, 'Sizes', pheightmax*ones(1,3) );

% Add some contents.
uicontrol( 'Style', 'PushButton', 'String', 'Button 1', 'Parent', panel{1} );
uicontrol( 'Style', 'PushButton', 'String', 'Button 2', 'Parent', panel{2} );
uicontrol( 'Style', 'PushButton', 'String', 'Button 3', 'Parent', panel{3} );

% Resize the window
pos = get( fig, 'Position' );
set( fig, 'Position', [pos(1,1:2),width,sum(box.Sizes)] );

Add the minimize/maximize callback

We set each panel to call the same minimize/maximize function. This function is nested inside the main function so that it has access to the main function's variables. A better way to do this is to make the main function into a class, but this nested-function approach is fine for simple applications.

Note that as soon as we set the "MinimizeFcn" property the minimize/maximize icon appears in the top-right of each panel. We use a cell-array to pass an extra argument, the panel number, to the minimize function. This extra argument appears after the usual eventSource and eventData arguments.

% Hook up the minimize callback.
set( panel{1}, 'MinimizeFcn', {@nMinimize, 1} );
set( panel{2}, 'MinimizeFcn', {@nMinimize, 2} );
set( panel{3}, 'MinimizeFcn', {@nMinimize, 3} );

%-------------------------------------------------------------------------%
 
    function nMinimize( eventSource, eventData, whichpanel )
        % A panel has been maximized/minimized
        s = get( box, 'Sizes' );
        pos = get( fig, 'Position' );
        panel{whichpanel}.IsMinimized = ~panel{whichpanel}.IsMinimized;
        if panel{whichpanel}.IsMinimized
            s(whichpanel) = pheightmin;
        else
            s(whichpanel) = pheightmax;
        end 
        set( box, 'Sizes', s );
        
        % Resize the figure, keeping the top stationary
        delta_height = pos(1,4) - sum( box.Sizes );
        set( fig, 'Position', pos(1,:) + [0 delta_height 0 -delta_height] );
    end % Minimize 

end % Main function

Click the minimize buttons

Minimizing the middle panel causes it to shrink to just its title-bar and the window shrinks accordingly. The "Minimize" icon is replaced by a "Maximise" icon.

Re-maximizing the panel would cause it to re-appear in full and the window to grow again.