copy the result or formula to clipboard on long press

app/src/main/java/com/simplemobiletools/calculator/MainActivity.java

@@ -1,5 +1,7 @@
 package com.simplemobiletools.calculator;
 
+import android.content.ClipData;
+import android.content.ClipboardManager;
 import android.content.Intent;
 import android.content.res.Resources;
 import android.os.Bundle;
@@ -122,6 +124,32 @@ public class MainActivity extends AppCompatActivity implements Calculator {
         calc.numpadClicked(id);
     }
 
+    @OnLongClick(R.id.formula)
+    public boolean formulaLongPressed() {
+        copyToClipboard(false);
+        return true;
+    }
+
+    @OnLongClick(R.id.result)
+    public boolean resultLongPressed() {
+        copyToClipboard(true);
+        return true;
+    }
+
+    private void copyToClipboard(boolean copyResult) {
+        String value;
+        if (copyResult) {
+            value = result.getText().toString();
+        } else {
+            value = formula.getText().toString();
+        }
+
+        final ClipboardManager clipboard = (ClipboardManager) getSystemService(CLIPBOARD_SERVICE);
+        final ClipData clip = ClipData.newPlainText(getResources().getString(R.string.app_name), value);
+        clipboard.setPrimaryClip(clip);
+        Utils.showToast(getApplicationContext(), R.string.copied_to_clipboard);
+    }
+
     @Override
     public void setValue(String value) {
         result.setText(value);

app/src/main/java/com/simplemobiletools/calculator/Utils.java

@@ -0,0 +1,10 @@
+package com.simplemobiletools.calculator;
+
+import android.content.Context;
+import android.widget.Toast;
+
+public class Utils {
+    public static void showToast(Context context, int resId) {
+        Toast.makeText(context, context.getResources().getString(resId), Toast.LENGTH_SHORT).show();
+    }
+}

app/src/main/res/values/strings.xml

@@ -1,5 +1,6 @@
 <resources>
     <string name="app_name">Simple Calculator</string>
+    <string name="copied_to_clipboard">Value copied to clipboard</string>
 
     <!-- About -->
     <string name="about">About</string>