1 package autotest.common.ui; 2 3 import autotest.common.SimpleCallback; 4 5 import com.google.gwt.event.dom.client.ClickEvent; 6 import com.google.gwt.event.dom.client.ClickHandler; 7 import com.google.gwt.user.client.ui.Anchor; 8 import com.google.gwt.user.client.ui.Composite; 9 import com.google.gwt.user.client.ui.FlowPanel; 10 import com.google.gwt.user.client.ui.HorizontalPanel; 11 import com.google.gwt.user.client.ui.Label; 12 import com.google.gwt.user.client.ui.Panel; 13 14 import java.util.ArrayList; 15 import java.util.List; 16 17 /** 18 * A widget to faciliate pagination of tables. Shows currently displayed rows, 19 * total row count, and buttons for moving among pages. 20 */ 21 public class Paginator extends Composite { 22 static class LinkWithDisable extends Composite { 23 protected Panel panel = new FlowPanel(); 24 protected Label label; 25 protected Anchor link; 26 LinkWithDisable(String text)27 public LinkWithDisable(String text) { 28 label = new Label(text); 29 link = new Anchor(text); 30 panel.add(link); 31 panel.add(label); 32 link.setStyleName("paginator-link"); 33 label.setStyleName("paginator-link"); 34 setEnabled(false); // default to not enabled 35 initWidget(panel); 36 } 37 setEnabled(boolean enabled)38 public void setEnabled(boolean enabled) { 39 link.setVisible(enabled); 40 label.setVisible(!enabled); 41 } 42 addClickHandler(ClickHandler handler)43 public void addClickHandler(ClickHandler handler) { 44 link.addClickHandler(handler); 45 } 46 } 47 48 protected int resultsPerPage, numTotalResults; 49 protected List<SimpleCallback> callbacks = new ArrayList<SimpleCallback>(); 50 protected int currentStart = 0; 51 52 protected HorizontalPanel mainPanel = new HorizontalPanel(); 53 protected LinkWithDisable nextControl, prevControl, 54 firstControl, lastControl; 55 protected Label statusLabel = new Label(); 56 Paginator()57 public Paginator() { 58 prevControl = new LinkWithDisable("< Previous"); 59 prevControl.addClickHandler(new ClickHandler() { 60 public void onClick(ClickEvent event) { 61 currentStart -= Paginator.this.resultsPerPage; 62 notifyCallbacks(); 63 } 64 }); 65 nextControl = new LinkWithDisable("Next >"); 66 nextControl.addClickHandler(new ClickHandler() { 67 public void onClick(ClickEvent event) { 68 currentStart += Paginator.this.resultsPerPage; 69 notifyCallbacks(); 70 } 71 }); 72 firstControl = new LinkWithDisable("<< First"); 73 firstControl.addClickHandler(new ClickHandler() { 74 public void onClick(ClickEvent event) { 75 currentStart = 0; 76 notifyCallbacks(); 77 } 78 }); 79 lastControl = new LinkWithDisable("Last >>"); 80 lastControl.addClickHandler(new ClickHandler() { 81 public void onClick(ClickEvent event) { 82 currentStart = getLastPageStart(); 83 notifyCallbacks(); 84 } 85 }); 86 87 statusLabel.setWidth("10em"); 88 statusLabel.setHorizontalAlignment(Label.ALIGN_CENTER); 89 90 mainPanel.setVerticalAlignment(HorizontalPanel.ALIGN_MIDDLE); 91 mainPanel.add(firstControl); 92 mainPanel.add(prevControl); 93 mainPanel.add(statusLabel); 94 mainPanel.add(nextControl); 95 mainPanel.add(lastControl); 96 97 initWidget(mainPanel); 98 } 99 100 /** 101 * Get the current starting row index. 102 */ getStart()103 public int getStart() { 104 return currentStart; 105 } 106 107 /** 108 * Get the current ending row index (one past the last currently displayed 109 * row). 110 */ getEnd()111 public int getEnd() { 112 int end = currentStart + resultsPerPage; 113 if (end < numTotalResults) 114 return end; 115 return numTotalResults; 116 } 117 118 /** 119 * Get the size of each page. 120 */ getResultsPerPage()121 public int getResultsPerPage() { 122 return resultsPerPage; 123 } 124 125 /** 126 * Set the size of a page. 127 */ setResultsPerPage(int resultsPerPage)128 public void setResultsPerPage(int resultsPerPage) { 129 this.resultsPerPage = resultsPerPage; 130 } 131 132 /** 133 * Set the total number of results in the current working set. 134 */ setNumTotalResults(int numResults)135 public void setNumTotalResults(int numResults) { 136 this.numTotalResults = numResults; 137 if (currentStart >= numResults) 138 currentStart = getLastPageStart(); 139 } 140 141 /** 142 * Set the current starting index. 143 */ setStart(int start)144 public void setStart(int start) { 145 this.currentStart = start; 146 } 147 getLastPageStart()148 protected int getLastPageStart() { 149 // compute start of last page using truncation 150 return ((numTotalResults - 1) / resultsPerPage) * resultsPerPage; 151 } 152 update()153 public void update() { 154 boolean prevEnabled = !(currentStart == 0); 155 boolean nextEnabled = currentStart + resultsPerPage < numTotalResults; 156 firstControl.setEnabled(prevEnabled); 157 prevControl.setEnabled(prevEnabled); 158 nextControl.setEnabled(nextEnabled); 159 lastControl.setEnabled(nextEnabled); 160 int displayStart = getStart() + 1; 161 if(numTotalResults == 0) 162 displayStart = 0; 163 statusLabel.setText(displayStart + "-" + getEnd() + 164 " of " + numTotalResults); 165 } 166 167 public void addCallback(SimpleCallback callback) { 168 callbacks.add(callback); 169 } 170 171 public void removeCallback(SimpleCallback callback) { 172 callbacks.remove(callback); 173 } 174 175 protected void notifyCallbacks() { 176 for (SimpleCallback callback : callbacks) { 177 callback.doCallback(this); 178 } 179 } 180 } 181