Cannot remove pie chart entries on Android

[ewpatton]

Describe the bug

Affects

• Designer
• Blocks editor
• Projects Explorer
• Companion
• Compiled apps
• Buildserver
• Debugging
• Other... (please describe)

Expected behavior

Trying to remove an existing entry in the pie chart gives the following error:

java.lang.NumberFormatException: For input string: "cherry"
at sun.misc.FloatingDecimal.readJavaFormatString(FloatingDecimal.java:2043)
at sun.misc.FloatingDecimal.parseFloat(FloatingDecimal.java:122)
at java.lang.Float.parseFloat(Float.java:451)
at com.google.appinventor.components.runtime.ChartData2D$2.run(ChartData2D.java:120) 
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1167) 
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:641) 
at java.lang.Thread.run(Thread.java:919) 

Steps to reproduce

1. Add a Chart and ChartData2D to a project
2. Populate the ChartData2D with some values via ElementsFromString, e.g., "apple,2,blueberry,3,cherry,5
3. Add a ChartData2D.RemoveEntry block to the block workspace to remove ("cherry",5) and use "Do It" to perform the behavior

[d1vyanshu-kumar]

Hello @ewpatton,
I'm a new MIT App Inventor contributor and tried to replicate the issue. I followed the steps mentioned, but when I click on "Do It," the option is disabled. I'm not sure why this is happening. I can share a screenshot if that helps

[SusanRatiLane]

Hello @ewpatton, I'm a new MIT App Inventor contributor and tried to replicate the issue. I followed the steps mentioned, but when I click on "Do It," the option is disabled. I'm not sure why this is happening.

Do you have the app loaded on the Companion, either on a physical device or emulator? Do It requires access to the Companion to work.

[ShreyashN16]

Hello everyone,

I wanted to provide additional clarification and confirm the steps I followed:

I replicated the issue using the latest version of the Companion on an Android device.
After populating ChartData2D with ElementsFromString and attempting to remove an entry (e.g., "cherry", 5), the app throws a NumberFormatException error.
It appears that the issue stems from the label ("cherry") being parsed as a numeric value.
Suggested Fix:

Update the ChartData2D.RemoveEntry logic to correctly distinguish between numeric values and string labels.
Implement a safeguard to prevent non-numeric labels from being parsed as floats.
Let me know if there's any additional debugging or testing you'd like me to perform.

Thank you!

[ewpatton]

@ShreyashN16 That sounds roughly correct but in theory people may still want to be able to use numeric labels, they will just have to be converted to strings first.

[ShreyashN16]

@ewpatton
You're absolutely right—numeric labels can be useful, especially when dealing with datasets. If the system mandates string labels, users can convert numeric labels to strings before adding them to the chart. For instance,
in Java:

int numericLabel = 123;
String label = Integer.toString(numericLabel;
// Add the label to the chart

This approach maintains flexibility while conforming to the current requirements. It might also be worth considering an enhancement where the system internally handles such conversions for better usability.

[cindyloo]

reproduced:

[cindyloo]

the code tries to parse the x, y entries in order to get the entry being removed and then to highlight the following one (I guess)

// Refresh Chart with new data
            resetHighlightAtIndex(index);

however, the code to determine the index fails if the x value is a real string (such as "apple") and hence doesn't properly parse as a float

so I think the best fix is to try to fetch the index from the List, but if we don't have a parseable X value, just set the index to 0

            int index = 0;
try {
              //get index of x and remove the color highlight at that index
              float xValue = Float.parseFloat(x);
              float yValue = Float.parseFloat(y);

              Entry currEntry = new Entry(xValue, yValue);
              index = dataModel.findEntryIndex(currEntry);
            } catch (NumberFormatException e) {
              // can't get an index if x is a string label with code above
            }

            dataModel.removeEntryFromTuple(pair);
            // Refresh Chart with new data
            resetHighlightAtIndex(index);
            onDataChange();

actually, the BEST way is to take advantage of the dataModel methods eg

      Entry currEntry = dataModel.getEntryFromTuple(pair);
or
      dataModel.addEntryFromTuple(pairLabelAsIndex);

if it fails in the form of a NumberFormatException, handle that error in ChartData2D addEntry and removeEntry

[ShreyashN16]

Thank you for the clarification, @ewpatton. I understand that numeric labels should still be supported but need to be converted to strings first. I'll look into ensuring that both numeric and string labels are handled properly while preventing unintended NumberFormatException errors. Would it be preferable to enforce this conversion automatically within the ChartData2D component, or should we require users to explicitly format their inputs before passing them? Also, I would love to contribute more to MIT App Inventor beyond this issue. If you could encourage me by adding me to your team for GSoC 2025, I would be highly motivated to work on more features and improvements. Looking forward to your thoughts!

…

On Sun, 5 Jan 2025 at 09:16, Evan W. Patton ***@***.***> wrote: @ShreyashN16 <https://github.com/ShreyashN16> That sounds roughly correct but in theory people may still want to be able to use numeric labels, they will just have to be converted to strings first. — Reply to this email directly, view it on GitHub <#3262 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/BN7QM73PGGI7GIFL6ZZFPRT2JCTKNAVCNFSM6AAAAABSPWB3KOVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDKNZRGQ4DSOBVGY> . You are receiving this because you were mentioned.Message ID: ***@***.***>

[cindyloo]

updating ChartData2D to work with both strings and numbers for the x value (coordinate or label).
Charts other than PieChart would also need some kind of initialization provision as PieChart has to handle key: value pairs like "apples": 2

    public PieEntry(float value, String label) {
        super(0.0F, value);
        this.label = label;
    }

otherwise, we will see errors in adb logcat as well as the add/removals will fail to work. We are catching the exception however...

02-19 13:32:22.387 23943 23943 E Form    : Form Screen1 ErrorOccurred, errorNumber = 4101, componentType = Chart, functionName = GetEntryFromTuple, messages = Invalid Chart Entry Value(s): apples, 2
02-19 13:32:22.394 23943 23943 E Form    : Form Screen1 ErrorOccurred, errorNumber = 4101, componentType = Chart, functionName = GetEntryFromTuple, messages = Invalid Chart Entry Value(s): banana, 1
02-19 13:32:22.394 23943 23943 E Form    : Form Screen1 ErrorOccurred, errorNumber = 4101, componentType = Chart, functionName = GetEntryFromTuple, messages = Invalid Chart Entry Value(s): oranages, 3

[cindyloo]

updated code will handle a NumberFormatException, calculate the index value of the label-as-x, and pass that again to the 'dataModel' addEntryFromTuple or getEntryFromTuple

[cindyloo]

assume that the index from Labels

 YailList labelList = container.Labels();
 int indexList = labelList.indexOf(x);

is not necessarily the same index as what may come back from

Entry currEntry = dataModel.getEntryFromTuple(pairFromLabel);
            int indexFromFind = dataModel.findEntryIndex(currEntry);

[cindyloo]

tested with labels and with numerical x values across all chart types