public void insert(String delta) {
String currentText = getText().toString();
int selectionHandle = getSelectionStart();
String textBeforeInsertionHandle = currentText.substring(0, selectionHandle);
String textAfterInsertionHandle = currentText.substring(selectionHandle, currentText.length());
// Add extra rules for decimal points and operators
if (delta.length() == 1) {
char text = delta.charAt(0);
// don't allow two dots in the same number
if (text == Constants.DECIMAL_POINT) {
int p = selectionHandle - 1;
while (p >= 0 && Solver.isDigit(getText().charAt(p))) {
if (getText().charAt(p) == Constants.DECIMAL_POINT) {
return;
}
--p;
}
p = selectionHandle;
while (p < getText().length() && Solver.isDigit(getText().charAt(p))) {
if (getText().charAt(p) == Constants.DECIMAL_POINT) {
return;
}
++p;
}
}
char prevChar = selectionHandle > 0 ? getText().charAt(selectionHandle - 1) : '\0';
// don't allow 2 successive minuses
if (text == Constants.MINUS && prevChar == Constants.MINUS) {
return;
}
// don't allow multiple successive operators
if (Solver.isOperator(text) && text != Constants.MINUS) {
while (Solver.isOperator(prevChar)) {
if (selectionHandle == 1) {
return;
}
--selectionHandle;
prevChar = selectionHandle > 0 ? getText().charAt(selectionHandle - 1) : '\0';
textBeforeInsertionHandle = textBeforeInsertionHandle.substring(0, selectionHandle);
}
}
}
mIsInserting = true;
setText(
textBeforeInsertionHandle + delta + BaseModule.SELECTION_HANDLE + textAfterInsertionHandle);
mIsInserting = false;
}
protected String removeFormatting(String input) {
input = input.replace(Constants.POWER_PLACEHOLDER, Constants.POWER);
if (mSolver != null) {
input = input.replace(String.valueOf(mSolver.getBaseModule().getSeparator()), "");
}
return input;
}
protected void onFormat(Editable s) {
String text = removeFormatting(s.toString());
// Get the selection handle, since we're setting text and that'll overwrite it
MutableInteger selectionHandle = new MutableInteger(getSelectionStart());
// Adjust the handle by removing any comas or spacing to the left
String cs = s.subSequence(0, selectionHandle.intValue()).toString();
selectionHandle.subtract(TextUtil.countOccurrences(cs, mSolver.getBaseModule().getSeparator()));
// Update the text with formatted (comas, etc) text
setText(Html.fromHtml(formatText(text, selectionHandle)));
setSelection(selectionHandle.intValue());
}
protected boolean saveHistory(String expr, String result, boolean ensureResult) {
if (mHistory == null) {
return false;
}
expr = cleanExpression(expr);
if (!ensureResult
|| (!TextUtils.isEmpty(expr)
&& !TextUtils.isEmpty(result)
&& !Solver.equal(expr, result)
&& (mHistory.current() == null || !mHistory.current().getFormula().equals(expr)))) {
mHistory.enter(expr, result);
return true;
}
return false;
}
@Override
public void onEvaluate(String expr, String result, int errorResourceId) {
if (mCurrentState == CalculatorState.INPUT || mCurrentState == CalculatorState.GRAPHING) {
if (result == null || Solver.equal(result, expr)) {
mResultEditText.setText(null);
} else {
mResultEditText.setText(result);
}
} else if (errorResourceId != INVALID_RES_ID) {
onError(errorResourceId);
} else if (saveHistory(expr, result, true)) {
mDisplayView.scrollToMostRecent();
onResult(result);
} else if (mCurrentState == CalculatorState.EVALUATE) {
// The current expression cannot be evaluated -> return to the input state.
setState(CalculatorState.INPUT);
}
invalidateEqualsButton();
}
protected String cleanExpression(String expr) {
expr = EquationFormatter.appendParenthesis(expr);
expr = Solver.clean(expr);
expr = mTokenizer.getLocalizedExpression(expr);
return expr;
}
