Repository: tapestry-5 Updated Branches: refs/heads/master 61bc522ee -> 68303b1d6
TAP5-2589: extend interface with methods that ease incremental paging Project: http://git-wip-us.apache.org/repos/asf/tapestry-5/repo Commit: http://git-wip-us.apache.org/repos/asf/tapestry-5/commit/4958b713 Tree: http://git-wip-us.apache.org/repos/asf/tapestry-5/tree/4958b713 Diff: http://git-wip-us.apache.org/repos/asf/tapestry-5/diff/4958b713 Branch: refs/heads/master Commit: 4958b713fff229c6b0f028a7226a719549cf4d5b Parents: 61bc522 Author: Jochen Kemnade <jochen.kemn...@eddyson.de> Authored: Fri Oct 13 09:51:52 2017 +0200 Committer: Jochen Kemnade <jochen.kemn...@eddyson.de> Committed: Fri Oct 13 09:51:52 2017 +0200 ---------------------------------------------------------------------- .../apache/tapestry5/grid/GridDataSource.java | 29 ++++++++++++++++++++ .../internal/grid/CollectionGridDataSource.java | 6 ++++ 2 files changed, 35 insertions(+) ---------------------------------------------------------------------- http://git-wip-us.apache.org/repos/asf/tapestry-5/blob/4958b713/tapestry-core/src/main/java/org/apache/tapestry5/grid/GridDataSource.java ---------------------------------------------------------------------- diff --git a/tapestry-core/src/main/java/org/apache/tapestry5/grid/GridDataSource.java b/tapestry-core/src/main/java/org/apache/tapestry5/grid/GridDataSource.java index 9ebe488..8fca800 100644 --- a/tapestry-core/src/main/java/org/apache/tapestry5/grid/GridDataSource.java +++ b/tapestry-core/src/main/java/org/apache/tapestry5/grid/GridDataSource.java @@ -23,6 +23,35 @@ import java.util.List; */ public interface GridDataSource { + + /** + * Return whether the data source is empty, i.e. does not have any rows available. + */ + default public boolean isEmpty() + { + return getAvailableRows(1) == 0; + } + + /** + * Return the number of rows available in the data source with an upper limit. + * If determining the total number of rows is expensive, this method should be overridden to provide a more + * efficient implementation. + * Please note that the default Grid pager will still determine the total number of rows, so for this to have + * an effect, a custom pager should be used. + * + * @param limit the upper limit + * @return the number of rows or {@code limit}, whichever is lower + */ + default public int getAvailableRows(final int limit) + { + int availableRows = getAvailableRows(); + if (availableRows >= limit) + { + return limit; + } + return availableRows; + } + /** * Returns the number of rows available in the data source. */ http://git-wip-us.apache.org/repos/asf/tapestry-5/blob/4958b713/tapestry-core/src/main/java/org/apache/tapestry5/internal/grid/CollectionGridDataSource.java ---------------------------------------------------------------------- diff --git a/tapestry-core/src/main/java/org/apache/tapestry5/internal/grid/CollectionGridDataSource.java b/tapestry-core/src/main/java/org/apache/tapestry5/internal/grid/CollectionGridDataSource.java index 414d146..63591b1 100644 --- a/tapestry-core/src/main/java/org/apache/tapestry5/internal/grid/CollectionGridDataSource.java +++ b/tapestry-core/src/main/java/org/apache/tapestry5/internal/grid/CollectionGridDataSource.java @@ -36,6 +36,12 @@ public class CollectionGridDataSource implements GridDataSource list = CollectionFactory.newList(collection); } + @Override + public boolean isEmpty() + { + return list.isEmpty(); + } + public int getAvailableRows() { return list.size();
