Accessing appdesigner objects properties from a function
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I am trying to create a basic calculator with every operator button calling the same function .I am able to do this with the button label as parameter and a switch case inside the called function to check the prameter and proceed accordingly. How can I improve the app in following terms:
- Not pass the label of operator button everytime. Can the button which was pushed be identified without passing the button label? Identifying the operator which is the button label is the goal here.
- Have a common buttonPushed callback for multiple buttons since they all call the same function.
- Possibly improve how i append the history cell.
properties (Access = private)
history = {'History'}; % Description
end
methods (Access = private)
function func(app,operator)
switch operator
case '+'
app.ResultEditField.Value = app.Number1EditField.Value+app.Number2EditField.Value;
case '-'
app.ResultEditField.Value = app.Number1EditField.Value-app.Number2EditField.Value;
case '*'
app.ResultEditField.Value = app.Number1EditField.Value*app.Number2EditField.Value;
case '/'
app.ResultEditField.Value = app.Number1EditField.Value/app.Number2EditField.Value;
end
a=sprintf('\n %d %c %d = %d',app.Number1EditField.Value,operator,app.Number2EditField.Value,app.ResultEditField.Value );
app.history(end+1)={char(a)};
end
end
% Callbacks that handle component events
methods (Access = private)
% Button pushed function: addButton
function addButtonPushed(app, event)
app.func(app.addButton.Text);
end
Answers (1)
Jon
on 20 Jan 2022
First, I'm not sure why you would want to just have a single button pushed callback for multiple buttons.
Why not just break that function up and have the appropriate line of code in the button pushed callback for each of the individual buttons. So for example have the button pushed callback for the plus button have just the line:
app.ResultEditField.Value = app.Number1EditField.Value+app.Number2EditField.Value;
Assuming you really want to have a common button pushed callback with the switch case as you show, you could have each individual button have a button pressed callback that called the common function with the operator argument set appropriately.
So for example the button pushed call back for plus would have the line of code:
func('+')
5 Comments
Biraj Khanal
on 20 Jan 2022
Edited: Biraj Khanal
on 20 Jan 2022
Jon
on 20 Jan 2022
I don't know if there is any advantage, but instead of sprintf you could use:
a = app.Number1EditField.Value + operator + app.Number2EditField.Value +...
" = " + app.ResultEditField.Value
which uses the ability of the + operator to convert values to strings https://www.mathworks.com/help/matlab/matlab_prog/represent-text-with-character-and-string-arrays.html
Jon
on 20 Jan 2022
I'm sorry but I'm not understanding your comment. Are you saying that my first approach (have a button pressed callback for each operation and perform the appropriate operation there) solve your problem, or is there still something else that you are trying to do?
By the way, if there is some specific code that depends upon which button is pushed and some other code that is done for every button push then you could use the following approach. Put the specific part in the button's button pushed callback. Put the common code in another function. Have each specific button pressed callback call first perform its specific operation and then call the common function
Biraj Khanal
on 21 Jan 2022
Jon
on 21 Jan 2022
I'm sorry. I'm not really understanding then what it is that you are trying to do but are unable to do.
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