Package icyllis.modernui.widget

Class Filter

java.lang.Object
icyllis.modernui.widget.Filter
public abstract class Filter extends Object

A filter constrains data with a filtering pattern.

Filters are usually created by Filterable classes.

Filtering operations performed by calling filter(CharSequence) or filter(CharSequence, FilterListener) are performed asynchronously. When these methods are called, a filtering request is posted in a request queue and processed later. Any call to one of these methods will cancel any previous non-executed filtering request.

See Also:

  • Constructor Details

    • Filter

      public Filter()

      Creates a new asynchronous filter.

  • Method Details

    • setDelayer

      public void setDelayer(Filter.Delayer delayer)
      Provide an interface that decides how long to delay the message for a given query. Useful for heuristics such as posting a delay for the delete key to avoid doing any work while the user holds down the delete key.
      Parameters:
      delayer - The delayer.

    • filter

      public final void filter(CharSequence constraint)

      Starts an asynchronous filtering operation. Calling this method cancels all previous non-executed filtering requests and posts a new filtering request that will be executed later.

      Parameters:
      constraint - the constraint used to filter the data
      See Also:

    • filter

      public final void filter(CharSequence constraint, Filter.FilterListener listener)

      Starts an asynchronous filtering operation. Calling this method cancels all previous non-executed filtering requests and posts a new filtering request that will be executed later.

      Upon completion, the listener is notified.

      Parameters:
      constraint - the constraint used to filter the data
      listener - a listener notified upon completion of the operation
      See Also:

    • performFiltering

      protected abstract Filter.FilterResults performFiltering(CharSequence constraint)

      Invoked in a worker thread to filter the data according to the constraint. Subclasses must implement this method to perform the filtering operation. Results computed by the filtering operation must be returned as a Filter.FilterResults that will then be published in the UI thread through publishResults(CharSequence, FilterResults).

      Contract: When the constraint is null, the original data must be restored.

      Parameters:
      constraint - the constraint used to filter the data
      Returns:
      the results of the filtering operation
      See Also:

    • publishResults

      protected abstract void publishResults(CharSequence constraint, Filter.FilterResults results)

      Invoked in the UI thread to publish the filtering results in the user interface. Subclasses must implement this method to display the results computed in performFiltering(java.lang.CharSequence).

      Parameters:
      constraint - the constraint used to filter the data
      results - the results of the filtering operation
      See Also:

    • convertResultToString

      public CharSequence convertResultToString(Object resultValue)

      Converts a value from the filtered set into a CharSequence. Subclasses should override this method to convert their results. The default implementation returns an empty String for null values or the default String representation of the value.

      Parameters:
      resultValue - the value to convert to a CharSequence
      Returns:
      a CharSequence representing the value