bikeshed/src/com/google/gwt/list/client/PagingTableListView.java - gwt - Git at Google

 /*
  * Copyright 2010 Google Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License"); you may not
  * use this file except in compliance with the License. You may obtain a copy of
  * the License at
  *
  * http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
  * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
  * License for the specific language governing permissions and limitations under
  * the License.
  */
 package com.google.gwt.list.client;

 import com.google.gwt.cells.client.ButtonCell;
 import com.google.gwt.cells.client.Mutator;
 import com.google.gwt.dom.client.Document;
 import com.google.gwt.dom.client.Element;
 import com.google.gwt.dom.client.EventTarget;
 import com.google.gwt.dom.client.Node;
 import com.google.gwt.dom.client.NodeList;
 import com.google.gwt.dom.client.Style;
 import com.google.gwt.dom.client.TableCellElement;
 import com.google.gwt.dom.client.TableElement;
 import com.google.gwt.dom.client.TableRowElement;
 import com.google.gwt.dom.client.Style.Display;
 import com.google.gwt.list.shared.ListEvent;
 import com.google.gwt.list.shared.ListHandler;
 import com.google.gwt.list.shared.ListModel;
 import com.google.gwt.list.shared.ListRegistration;
 import com.google.gwt.list.shared.SizeChangeEvent;
 import com.google.gwt.user.client.Event;
 import com.google.gwt.user.client.ui.Widget;

 import java.util.ArrayList;
 import java.util.List;

 public class PagingTableListView<T> extends Widget {

   private int pageSize;
   private int numPages;
   private ListRegistration listReg;
   protected int curPage;
   private int totalSize;
   private List<Column<T, ?>> columns = new ArrayList<Column<T, ?>>();
   private ArrayList<T> data = new ArrayList<T>();
   private ButtonCell prevButton = new ButtonCell();
   private ButtonCell nextButton = new ButtonCell();

   public PagingTableListView(ListModel<T> listModel, final int pageSize) {
     this.pageSize = pageSize;
     setElement(Document.get().createTableElement());
     createRows();

     // TODO: total hack.
     sinkEvents(Event.MOUSEEVENTS | Event.KEYEVENTS);

     // Attach to the list model.
     listReg = listModel.addListHandler(new ListHandler<T>() {
       public void onDataChanged(ListEvent<T> event) {
         render(event.getStart(), event.getLength(), event.getValues());
       }

       public void onSizeChanged(SizeChangeEvent event) {
         totalSize = event.getSize();
         if (totalSize <= 0) {
           numPages = 0;
         } else {
           numPages = 1 + (totalSize - 1) / pageSize;
         }
         setPage(curPage);
       }
     });
     listReg.setRangeOfInterest(0, pageSize);
   }

   // TODO: remove(Column)
   public void addColumn(Column<T, ?> col) {
     columns.add(col);
     createRows();
     setPage(curPage); // TODO: better way to refresh?
   }

   @Override
   public void onBrowserEvent(Event event) {
     EventTarget target = event.getEventTarget();
     Node node = Node.as(target);
     while (node != null) {
       if (Element.is(node)) {
         Element elem = Element.as(node);

         // TODO: We need is() implementations in all Element subclasses.
         String tagName = elem.getTagName();
         if ("td".equalsIgnoreCase(tagName)) {
           TableCellElement td = TableCellElement.as(elem);
           TableRowElement tr = TableRowElement.as(td.getParentElement());

           // TODO: row/col assertions.
           int row = tr.getRowIndex(), col = td.getCellIndex();
           if (row < pageSize) {
             T value = data.get(row);
             Column<T, ?> column = columns.get(col);
             column.onBrowserEvent(elem, value, event);
           } else if (row == pageSize) {
             if (col == 0) {
               prevButton.onBrowserEvent(elem, null, event, new Mutator<String,String>() {
                 public void mutate(String object, String after) {
                   previousPage();
                 }
               });
             } else if (col == 2) {
               nextButton.onBrowserEvent(elem, null, event, new Mutator<String,String>() {
                 public void mutate(String object, String after) {
                   nextPage();
                 }
               });
             }
           }
           break;
         }
       }

       node = node.getParentNode();
     }
   }

   protected void render(int start, int length, List<T> values) {
     TableElement table = getElement().cast();
     int numCols = columns.size();
     int pageStart = curPage * pageSize;

     NodeList<TableRowElement> rows = table.getRows();
     for (int r = start; r < start + length; ++r) {
       TableRowElement row = rows.getItem(r - pageStart);
       T q = values.get(r - start);

       data.set(r - pageStart, q);
       for (int c = 0; c < numCols; ++c) {
         TableCellElement cell = row.getCells().getItem(c);
         StringBuilder sb = new StringBuilder();
         columns.get(c).render(q, sb);
         cell.setInnerHTML(sb.toString());

         // TODO: really total hack!
         Element child = cell.getFirstChildElement();
         if (child != null) {
           Event.sinkEvents(child, Event.ONCHANGE | Event.ONFOCUS | Event.ONBLUR);
         }
       }
     }
   }

   /**
    * Get the current page.
    *
    * @return the current page
    */
   public int getPage() {
     return curPage;
   }

   public void nextPage() {
     setPage(curPage + 1);
   }

   public void previousPage() {
     setPage(curPage - 1);
   }

   /**
    * Set the current visible page.
    *
    * @param page the page index
    */
   public void setPage(int page) {
     int newPage = Math.min(page, numPages - 1);
     newPage = Math.max(0, newPage);

     // Update the text showing the page number.
     updatePageText(newPage);

     // Early exit if we are already on the right page.
     if (curPage != newPage) {
       curPage = newPage;
       listReg.setRangeOfInterest(curPage * pageSize, pageSize);
     }

     updateRowVisibility();
   }

   private void updateRowVisibility() {
     int visible = Math.min(pageSize, totalSize - curPage * pageSize);

     TableElement table = getElement().cast();
     for (int r = 0; r < pageSize; ++r) {
       Style rowStyle = table.getRows().getItem(r).getStyle();
       if (r < visible) {
         rowStyle.clearDisplay();
       } else {
         rowStyle.setDisplay(Display.NONE);
       }
     }
   }

   /**
    * Set the number of rows per page.
    *
    * @param pageSize the page size
    */
   public void setPageSize(int pageSize) {
     if (this.pageSize == pageSize) {
       return;
     }
     this.pageSize = pageSize;
     curPage = -1;
     setPage(curPage);
   }

   /**
    * Update the text that shows the current page.
    *
    * @param page the current page
    */
   private void updatePageText(int page) {
     TableElement table = getElement().cast();
     NodeList<TableRowElement> rows = table.getRows();
     String text = "Page " + (page + 1) + " of " + numPages;
     rows.getItem(rows.getLength() - 1).getCells().getItem(1).setInnerText(text);
   }

   private void createRows() {
     TableElement table = getElement().cast();
     int numCols = columns.size();

     // TODO - only delete as needed
     int numRows = table.getRows().getLength();
     while (numRows-- > 0) {
       table.deleteRow(0);
     }

     for (int r = 0; r < pageSize; ++r) {
       TableRowElement row = table.insertRow(0);
       row.setClassName("pagingTableListView " + ((r & 0x1) == 0 ? "evenRow" : "oddRow"));

       // TODO: use cloneNode() to make this even faster.
       for (int c = 0; c < numCols; ++c) {
         row.insertCell(c);
       }
     }

     // Add the final row containing paging buttons
     TableRowElement pageRow = table.insertRow(pageSize);
     pageRow.insertCell(0);
     pageRow.insertCell(1);
     pageRow.insertCell(2);

     StringBuilder sb;

     sb = new StringBuilder();
     prevButton.render("Previous", sb);
     pageRow.getCells().getItem(0).setInnerHTML(sb.toString());

     pageRow.getCells().getItem(1).setAttribute("colspan", "" + (numCols - 2));
     pageRow.getCells().getItem(1).setAttribute("align", "center");

     sb = new StringBuilder();
     nextButton.render("Next", sb);
     pageRow.getCells().getItem(2).setInnerHTML(sb.toString());
     pageRow.getCells().getItem(2).setAttribute("align", "right");

     // Make room for the data cache
     data.ensureCapacity(pageSize);
     while (data.size() < pageSize) {
       data.add(null);
     }
   }
 }
	/*
	* Copyright 2010 Google Inc.
	*
	* Licensed under the Apache License, Version 2.0 (the "License"); you may not
	* use this file except in compliance with the License. You may obtain a copy of
	* the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
	* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
	* License for the specific language governing permissions and limitations under
	* the License.
	*/
	package com.google.gwt.list.client;

	import com.google.gwt.cells.client.ButtonCell;
	import com.google.gwt.cells.client.Mutator;
	import com.google.gwt.dom.client.Document;
	import com.google.gwt.dom.client.Element;
	import com.google.gwt.dom.client.EventTarget;
	import com.google.gwt.dom.client.Node;
	import com.google.gwt.dom.client.NodeList;
	import com.google.gwt.dom.client.Style;
	import com.google.gwt.dom.client.TableCellElement;
	import com.google.gwt.dom.client.TableElement;
	import com.google.gwt.dom.client.TableRowElement;
	import com.google.gwt.dom.client.Style.Display;
	import com.google.gwt.list.shared.ListEvent;
	import com.google.gwt.list.shared.ListHandler;
	import com.google.gwt.list.shared.ListModel;
	import com.google.gwt.list.shared.ListRegistration;
	import com.google.gwt.list.shared.SizeChangeEvent;
	import com.google.gwt.user.client.Event;
	import com.google.gwt.user.client.ui.Widget;

	import java.util.ArrayList;
	import java.util.List;

	public class PagingTableListView<T> extends Widget {

	private int pageSize;
	private int numPages;
	private ListRegistration listReg;
	protected int curPage;
	private int totalSize;
	private List<Column<T, ?>> columns = new ArrayList<Column<T, ?>>();
	private ArrayList<T> data = new ArrayList<T>();
	private ButtonCell prevButton = new ButtonCell();
	private ButtonCell nextButton = new ButtonCell();

	public PagingTableListView(ListModel<T> listModel, final int pageSize) {
	this.pageSize = pageSize;
	setElement(Document.get().createTableElement());
	createRows();

	// TODO: total hack.
	sinkEvents(Event.MOUSEEVENTS \| Event.KEYEVENTS);

	// Attach to the list model.
	listReg = listModel.addListHandler(new ListHandler<T>() {
	public void onDataChanged(ListEvent<T> event) {
	render(event.getStart(), event.getLength(), event.getValues());
	}

	public void onSizeChanged(SizeChangeEvent event) {
	totalSize = event.getSize();
	if (totalSize <= 0) {
	numPages = 0;
	} else {
	numPages = 1 + (totalSize - 1) / pageSize;
	}
	setPage(curPage);
	}
	});
	listReg.setRangeOfInterest(0, pageSize);
	}

	// TODO: remove(Column)
	public void addColumn(Column<T, ?> col) {
	columns.add(col);
	createRows();
	setPage(curPage); // TODO: better way to refresh?
	}

	@Override
	public void onBrowserEvent(Event event) {
	EventTarget target = event.getEventTarget();
	Node node = Node.as(target);
	while (node != null) {
	if (Element.is(node)) {
	Element elem = Element.as(node);

	// TODO: We need is() implementations in all Element subclasses.
	String tagName = elem.getTagName();
	if ("td".equalsIgnoreCase(tagName)) {
	TableCellElement td = TableCellElement.as(elem);
	TableRowElement tr = TableRowElement.as(td.getParentElement());

	// TODO: row/col assertions.
	int row = tr.getRowIndex(), col = td.getCellIndex();
	if (row < pageSize) {
	T value = data.get(row);
	Column<T, ?> column = columns.get(col);
	column.onBrowserEvent(elem, value, event);
	} else if (row == pageSize) {
	if (col == 0) {
	prevButton.onBrowserEvent(elem, null, event, new Mutator<String,String>() {
	public void mutate(String object, String after) {
	previousPage();
	}
	});
	} else if (col == 2) {
	nextButton.onBrowserEvent(elem, null, event, new Mutator<String,String>() {
	public void mutate(String object, String after) {
	nextPage();
	}
	});
	}
	}
	break;
	}
	}

	node = node.getParentNode();
	}
	}

	protected void render(int start, int length, List<T> values) {
	TableElement table = getElement().cast();
	int numCols = columns.size();
	int pageStart = curPage * pageSize;

	NodeList<TableRowElement> rows = table.getRows();
	for (int r = start; r < start + length; ++r) {
	TableRowElement row = rows.getItem(r - pageStart);
	T q = values.get(r - start);

	data.set(r - pageStart, q);
	for (int c = 0; c < numCols; ++c) {
	TableCellElement cell = row.getCells().getItem(c);
	StringBuilder sb = new StringBuilder();
	columns.get(c).render(q, sb);
	cell.setInnerHTML(sb.toString());

	// TODO: really total hack!
	Element child = cell.getFirstChildElement();
	if (child != null) {
	Event.sinkEvents(child, Event.ONCHANGE \| Event.ONFOCUS \| Event.ONBLUR);
	}
	}
	}
	}

	/**
	* Get the current page.
	*
	* @return the current page
	*/
	public int getPage() {
	return curPage;
	}

	public void nextPage() {
	setPage(curPage + 1);
	}

	public void previousPage() {
	setPage(curPage - 1);
	}

	/**
	* Set the current visible page.
	*
	* @param page the page index
	*/
	public void setPage(int page) {
	int newPage = Math.min(page, numPages - 1);
	newPage = Math.max(0, newPage);

	// Update the text showing the page number.
	updatePageText(newPage);

	// Early exit if we are already on the right page.
	if (curPage != newPage) {
	curPage = newPage;
	listReg.setRangeOfInterest(curPage * pageSize, pageSize);
	}

	updateRowVisibility();
	}

	private void updateRowVisibility() {
	int visible = Math.min(pageSize, totalSize - curPage * pageSize);

	TableElement table = getElement().cast();
	for (int r = 0; r < pageSize; ++r) {
	Style rowStyle = table.getRows().getItem(r).getStyle();
	if (r < visible) {
	rowStyle.clearDisplay();
	} else {
	rowStyle.setDisplay(Display.NONE);
	}
	}
	}

	/**
	* Set the number of rows per page.
	*
	* @param pageSize the page size
	*/
	public void setPageSize(int pageSize) {
	if (this.pageSize == pageSize) {
	return;
	}
	this.pageSize = pageSize;
	curPage = -1;
	setPage(curPage);
	}

	/**
	* Update the text that shows the current page.
	*
	* @param page the current page
	*/
	private void updatePageText(int page) {
	TableElement table = getElement().cast();
	NodeList<TableRowElement> rows = table.getRows();
	String text = "Page " + (page + 1) + " of " + numPages;
	rows.getItem(rows.getLength() - 1).getCells().getItem(1).setInnerText(text);
	}

	private void createRows() {
	TableElement table = getElement().cast();
	int numCols = columns.size();

	// TODO - only delete as needed
	int numRows = table.getRows().getLength();
	while (numRows-- > 0) {
	table.deleteRow(0);
	}

	for (int r = 0; r < pageSize; ++r) {
	TableRowElement row = table.insertRow(0);
	row.setClassName("pagingTableListView " + ((r & 0x1) == 0 ? "evenRow" : "oddRow"));

	// TODO: use cloneNode() to make this even faster.
	for (int c = 0; c < numCols; ++c) {
	row.insertCell(c);
	}
	}

	// Add the final row containing paging buttons
	TableRowElement pageRow = table.insertRow(pageSize);
	pageRow.insertCell(0);
	pageRow.insertCell(1);
	pageRow.insertCell(2);

	StringBuilder sb;

	sb = new StringBuilder();
	prevButton.render("Previous", sb);
	pageRow.getCells().getItem(0).setInnerHTML(sb.toString());

	pageRow.getCells().getItem(1).setAttribute("colspan", "" + (numCols - 2));
	pageRow.getCells().getItem(1).setAttribute("align", "center");

	sb = new StringBuilder();
	nextButton.render("Next", sb);
	pageRow.getCells().getItem(2).setInnerHTML(sb.toString());
	pageRow.getCells().getItem(2).setAttribute("align", "right");

	// Make room for the data cache
	data.ensureCapacity(pageSize);
	while (data.size() < pageSize) {
	data.add(null);
	}
	}
	}