CODEWITHSUNDEEP
javaandroidfor-loop
Chase
Chase

Reputation: 5615

What's a fast way to assign buttons in a loop at the start of an activity?

I've a piece of code that is called at the start of onCreate() (5th line after super.onCreate) in my Main Activity that I suspect is slowing down the start (and debugging).

It's a loop used to assign 10 buttons along with Click listeners for each of them. Here's the snippet-

//expostate is a boolean and is always false at start of activity
//checkLength(Screen) will always return true at start of activity
//expression is of String data type
//Screen is a TextView

for(int i=0; i<10; i++){
            String btnid = "btn" + i;
            int resourceid = getResources().getIdentifier(btnid, "id", getPackageName());
            numbuttons[i] = findViewById(resourceid);
            final String value =  String.valueOf(i);
            numbuttons[i].setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {
                    if (checkLength(Screen) && !expostate) {
                        if (expression.equals("0")) {
                            expression = "";
                            Screen.setText("");
                        }
                        Screen.append(value);
                        expression += value;
                        presentop = false;
                    }
                    else if (checkLength(Screen) && expostate) {
                        if (expression.equals("0")) { 
                            expression = "";
                            Screen.setText("");
                        }
                        Screen.append(getSuperscript(value));
                        expression += value;
                        presentop = false;
                    }
                }
            });
        }

Is there a better/faster way to achieve this same task?

Upvotes: 0

Views: 60

Answers (3)

Chase
Chase

Reputation: 5615

So, I found out that a less janky way to do this is assigning android:onClick to each of the 10 buttons along with an android:tag to extract value.

The Code:-

public void onNumpress(View v){
        buttonFlash((Button) v);
        String value = getResources().getResourceEntryName(v.getId()).replace("btn", "");
        if (expression.equals("0")) {
            expression = "";
            Screen.setText("");
        }
        if (checkLength(Screen)) Screen.append(expostate ? getSuperscript(value) : value);
        expression += value;
        presentop = false;
    }

The xml layout of one of the buttons:-

    <Button
        android:id="@+id/btn0"
        android:layout_width="78dp"
        android:layout_height="85dp"
        android:layout_marginBottom="8dp"
        android:background="@color/colorPrimary"
        android:text="@string/btn0"
        android:textColor="@color/colorSecondary"
        android:textSize="24sp"
        android:onClick="onNumpress"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintStart_toEndOf="@+id/btnans" />

Upvotes: 0

forpas
forpas

Reputation: 164139

An improvement I would suggest is for the onClick() method.
Your logic can be written like this:

public void onClick(View view) {
    if (expression.equals("0")) {
        expression = "";
        Screen.setText("");
    }

    if (checkLength(Screen)) Screen.append(expostate ? getSuperscript(value) : value);

    expression += value;
    presentop = false;
}

Upvotes: 1

DKIT
DKIT

Reputation: 3481

If the ID's of the buttons are known at runtime you would be better off just creating an array with the ID's instead of doing the getResources()-call.

Upvotes: 0

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