Upgrade to ExtJS 4.0.0 - Released 04/26/2011

[extjs.git] / src / grid / feature / Chunking.js

diff --git a/src/grid/feature/Chunking.js b/src/grid/feature/Chunking.js
new file mode 100644 (file)
index 0000000..831d054
--- /dev/null
+++ b/src/grid/feature/Chunking.js
@@ -0,0 +1,82 @@
+/**
+ * @class Ext.grid.feature.Chunking
+ * @extends Ext.grid.feature.Feature
+ */
+Ext.define('Ext.grid.feature.Chunking', {
+    extend: 'Ext.grid.feature.Feature',
+    alias: 'feature.chunking',
+    
+    chunkSize: 20,
+    rowHeight: Ext.isIE ? 27 : 26,
+    visibleChunk: 0,
+    hasFeatureEvent: false,
+    attachEvents: function() {
+        var grid = this.view.up('gridpanel'),
+            scroller = grid.down('gridscroller[dock=right]');
+        scroller.el.on('scroll', this.onBodyScroll, this, {buffer: 300});
+        //this.view.on('bodyscroll', this.onBodyScroll, this, {buffer: 300});
+    },
+    
+    onBodyScroll: function(e, t) {
+        var view = this.view,
+            top  = t.scrollTop,
+            nextChunk = Math.floor(top / this.rowHeight / this.chunkSize);
+        if (nextChunk !== this.visibleChunk) {
+        
+            this.visibleChunk = nextChunk;
+            view.refresh();
+            view.el.dom.scrollTop = top;
+            //BrowserBug: IE6,7,8 quirks mode takes setting scrollTop 2x.
+            view.el.dom.scrollTop = top;
+        }
+    },
+    
+    collectData: function(records, preppedRecords, startIndex, fullWidth, orig) {
+        var o = {
+            fullWidth: orig.fullWidth,
+            chunks: []
+        },
+        //headerCt = this.view.headerCt,
+        //colums = headerCt.getColumnsForTpl(),
+        recordCount = orig.rows.length,
+        start = 0,
+        i = 0,
+        visibleChunk = this.visibleChunk,
+        chunk,
+        rows,
+        chunkLength;
+
+        for (; start < recordCount; start+=this.chunkSize, i++) {
+            if (start+this.chunkSize > recordCount) {
+                chunkLength = recordCount - start;
+            } else {
+                chunkLength = this.chunkSize;
+            }
+            
+            if (i >= visibleChunk - 1 && i <= visibleChunk + 1) {
+                rows = orig.rows.slice(start, start+this.chunkSize);
+            } else {
+                rows = [];
+            }
+            o.chunks.push({
+                rows: rows,
+                fullWidth: fullWidth,
+                chunkHeight: chunkLength * this.rowHeight
+            });
+        }
+        
+        
+        return o;
+    },
+    
+    getTableFragments: function() {
+        return {
+            openTableWrap: function() {
+                return '<tpl for="chunks"><div class="' + Ext.baseCSSPrefix + 'grid-chunk" style="height: {chunkHeight}px;">';
+            },
+            closeTableWrap: function() {
+                return '</div></tpl>';
+            }
+        };
+    }
+});