/**
* This method will draw onto the canvas the appropriate UI state of each column dictated
* by {@param animationProgress}. As a side effect, this method will also translate the canvas
* accordingly for the draw procedures.
*/
public void draw(Canvas canvas, Paint textPaint)
{
for (int i = 0, size = tickerColumns.Count; i < size; i++)
{
TickerColumn column = tickerColumns[i];
column.draw(canvas, textPaint);
canvas.Translate(column.getCurrentWidth(), 0f);
}
}
/**
* Tell the column manager the new target text that it should display.
*/
public void setText(char[] text)
{
if (characterLists == null)
{
throw new Exception("Need to call #setCharacterLists first.");
}
// First remove any zero-width columns
for (int i = 0; i < tickerColumns.Count;)
{
TickerColumn tickerColumn = tickerColumns[i];
if (tickerColumn.getCurrentWidth() > 0)
{
i++;
}
else
{
tickerColumns.Remove(tickerColumn);
}
}
// Use Levenshtein distance algorithm to figure out how to manipulate the columns
int[] actions = LevenshteinUtils.computeColumnActions(
getCurrentText(), text, supportedCharacters
);
int columnIndex = 0;
int textIndex = 0;
for (int i = 0; i < actions.Length; i++)
{
switch (actions[i])
{
case LevenshteinUtils.ACTION_INSERT:
tickerColumns.Insert(columnIndex,
new TickerColumn(characterLists, metrics)); break;
// Intentional fallthrough
case LevenshteinUtils.ACTION_SAME:
tickerColumns[columnIndex].setTargetChar(text[textIndex]);
columnIndex++;
textIndex++;
break;
case LevenshteinUtils.ACTION_DELETE:
tickerColumns[columnIndex].setTargetChar(TickerUtils.EMPTY_CHAR);
columnIndex++;
break;
default:
throw new Exception("Unknown action: " + actions[i]);
}
}
}