/**
* Add item to the model.
*
* <p>If the item has no color, this will define its color based on the model's next available
* color.
*
* <p>If the model is already 'running', the item will be 'start'ed.
*
* @param item {@link ModelItem} to add
* @throws RuntimeException if item is already in model
* @throws Exception on error trying to start a PV Item that's added to a running model
*/
public void addItem(final ModelItem item) throws Exception {
// A new item with the same PV name are allowed to be added in the
// model. This way Data Browser can show the trend of the same PV
// in different axes or with different waveform indexes. For example,
// one may want to show the first element of epics://aaa:bbb in axis 1
// while showing the third element of the same PV in axis 2 to compare
// their trends in one chart.
//
// if (getItem(item.getName()) != null)
// throw new RuntimeException("Item " + item.getName() + " already in Model");
// But, if exactly the same instance of the given ModelItem already exists in this
// model, it will not be added.
if (items.indexOf(item) != -1)
throw new RuntimeException("Item " + item.getName() + " already in Model");
// Assign default color
if (item.getColor() == null) item.setColor(getNextItemColor());
// Force item to be on an axis
if (item.getAxis() == null) {
if (axes.size() == 0) addAxis(item.getDisplayName());
item.setAxis(axes.get(0));
}
// Check item axis
if (!axes.contains(item.getAxis()))
throw new Exception("Item " + item.getName() + " added with invalid axis " + item.getAxis());
// Add to model
items.add(item);
item.setModel(this);
if (is_running && item instanceof PVItem) ((PVItem) item).start(scanner);
// Notify listeners of new item
for (ModelListener listener : listeners) listener.itemAdded(item);
}
/**
* Remove item from the model.
*
* <p>If the model and thus item are 'running', the item will be 'stopped'.
*
* @param item
* @throws RuntimeException if item is already in model
*/
public void removeItem(final ModelItem item) {
if (is_running && item instanceof PVItem) {
final PVItem pv = (PVItem) item;
pv.stop();
// Delete its samples:
// For one, so save memory.
// Also, in case item is later added back in, its old samples
// will have gaps because the item was stopped
pv.getSamples().clear();
}
if (!items.remove(item)) throw new RuntimeException("Unknown item " + item.getName());
// Detach item from model
item.setModel(null);
// Notify listeners of removed item
for (ModelListener listener : listeners) listener.itemRemoved(item);
// Remove axis if unused
AxisConfig axis = item.getAxis();
item.setAxis(null);
if (countActiveItemsOnAxis(axis) == 0) {
removeAxis(axis);
fireAxisChangedEvent(null);
}
}
/**
* @param axis Axis to remove
* @throws Error when axis not in model, or axis in use by model item
*/
public void removeAxis(final AxisConfig axis) {
if (!axes.contains(axis)) throw new Error("Unknown AxisConfig");
for (ModelItem item : items)
if (item.getAxis() == axis) throw new Error("Cannot removed AxisConfig while in use");
axis.setModel(null);
axes.remove(axis);
fireAxisChangedEvent(null);
}
/**
* @param axis Axis to test
* @return ModelItem linked to this axis count
*/
public int countActiveItemsOnAxis(final AxisConfig axis) {
int count = 0;
for (ModelItem item : items) if (item.getAxis() == axis && item.isVisible()) count++;
return count;
}
/**
* @param axis Axis to test
* @return First ModelItem that uses the axis, <code>null</code> if axis is empty
*/
public ModelItem getFirstItemOnAxis(final AxisConfig axis) {
for (ModelItem item : items) if (item.getAxis() == axis) return item;
return null;
}
