/**
* Creates a new graphical view.
*
* @param view the graphical view
* @param chart the chart to be drawn
*/
public TouchHandler(GraphicalView view, AbstractChart chart) {
graphicalView = view;
zoomR = graphicalView.getZoomRectangle();
if (chart instanceof XYChart) {
mRenderer = ((XYChart) chart).getRenderer();
} else {
mRenderer = ((RoundChart) chart).getRenderer();
}
if (mRenderer.isPanEnabled()) {
mPan = new Pan(chart);
}
if (mRenderer.isZoomEnabled()) {
mPinchZoom = new Zoom(chart, true, 1);
}
}
/**
* Handles the touch event.
*
* @param event the touch event
*/
public boolean handleTouch(MotionEvent event) {
int action = event.getAction();
if (mRenderer != null && action == MotionEvent.ACTION_MOVE) {
if (oldX >= 0 || oldY >= 0) {
float newX = event.getX(0);
float newY = event.getY(0);
if (event.getPointerCount() > 1
&& (oldX2 >= 0 || oldY2 >= 0)
&& mRenderer.isZoomEnabled()) {
float newX2 = event.getX(1);
float newY2 = event.getY(1);
float newDeltaX = Math.abs(newX - newX2);
float newDeltaY = Math.abs(newY - newY2);
float oldDeltaX = Math.abs(oldX - oldX2);
float oldDeltaY = Math.abs(oldY - oldY2);
float zoomRate = 1;
float tan1 = Math.abs(newY - oldY) / Math.abs(newX - oldX);
float tan2 = Math.abs(newY2 - oldY2) / Math.abs(newX2 - oldX2);
if (tan1 <= 0.25 && tan2 <= 0.25) {
// horizontal pinch zoom, |deltaY| / |deltaX| is [0 ~ 0.25], 0.25 is
// the approximate value of tan(PI / 12)
zoomRate = newDeltaX / oldDeltaX;
applyZoom(zoomRate, Zoom.ZOOM_AXIS_X);
} else if (tan1 >= 3.73 && tan2 >= 3.73) {
// pinch zoom vertically, |deltaY| / |deltaX| is [3.73 ~ infinity],
// 3.732 is the approximate value of tan(PI / 2 - PI / 12)
zoomRate = newDeltaY / oldDeltaY;
applyZoom(zoomRate, Zoom.ZOOM_AXIS_Y);
} else {
// pinch zoom diagonally
if (Math.abs(newX - oldX) >= Math.abs(newY - oldY)) {
zoomRate = newDeltaX / oldDeltaX;
} else {
zoomRate = newDeltaY / oldDeltaY;
}
applyZoom(zoomRate, Zoom.ZOOM_AXIS_XY);
}
oldX2 = newX2;
oldY2 = newY2;
} else if (mRenderer.isPanEnabled()) {
mPan.apply(oldX, oldY, newX, newY);
oldX2 = 0;
oldY2 = 0;
}
oldX = newX;
oldY = newY;
graphicalView.repaint();
return true;
}
} else if (action == MotionEvent.ACTION_DOWN) {
oldX = event.getX(0);
oldY = event.getY(0);
if (mRenderer != null && mRenderer.isZoomEnabled() && zoomR.contains(oldX, oldY)) {
if (oldX < zoomR.left + zoomR.width() / 3) {
graphicalView.zoomIn();
} else if (oldX < zoomR.left + zoomR.width() * 2 / 3) {
graphicalView.zoomOut();
} else {
graphicalView.zoomReset();
}
return true;
}
} else if (action == MotionEvent.ACTION_UP || action == MotionEvent.ACTION_POINTER_UP) {
oldX = 0;
oldY = 0;
oldX2 = 0;
oldY2 = 0;
if (action == MotionEvent.ACTION_POINTER_UP) {
oldX = -1;
oldY = -1;
}
}
return !mRenderer.isClickEnabled();
}