michael@0: const nsIDOMKeyEvent = Components.interfaces.nsIDOMKeyEvent;
michael@0: 
michael@0: /**
michael@0:  * Create grid object based on HTML table.
michael@0:  */
michael@0: function grid(aTableIdentifier)
michael@0: {
michael@0:   this.getRowCount = function getRowCount()
michael@0:   {
michael@0:     return this.table.rows.length - (this.table.tHead ? 1 : 0);
michael@0:   }
michael@0:   this.getColsCount = function getColsCount()
michael@0:   {
michael@0:     return this.table.rows[0].cells.length;
michael@0:   }
michael@0: 
michael@0:   this.getRowAtIndex = function getRowAtIndex(aIndex)
michael@0:   {
michael@0:     return this.table.rows[this.table.tHead ? aIndex + 1 : aIndex];
michael@0:   }
michael@0: 
michael@0:   this.getMaxIndex = function getMaxIndex()
michael@0:   {
michael@0:     return this.getRowCount() * this.getColsCount() - 1;
michael@0:   }
michael@0: 
michael@0:   this.getCellAtIndex = function getCellAtIndex(aIndex)
michael@0:   {
michael@0:     var rowCount = this.getRowCount();
michael@0:     var colsCount = this.getColsCount();
michael@0: 
michael@0:     var rowIdx = Math.floor(aIndex / colsCount);
michael@0:     var colIdx = aIndex % colsCount;
michael@0: 
michael@0:     var row = this.getRowAtIndex(rowIdx);
michael@0:     return row.cells[colIdx];
michael@0:   }
michael@0: 
michael@0:   this.getIndexByCell = function getIndexByCell(aCell)
michael@0:   {
michael@0:     var colIdx = aCell.cellIndex;
michael@0: 
michael@0:     var rowIdx = aCell.parentNode.rowIndex;
michael@0:     if (this.table.tHead)
michael@0:       rowIdx -= 1;
michael@0: 
michael@0:     var colsCount = this.getColsCount();
michael@0:     return rowIdx * colsCount + colIdx;
michael@0:   }
michael@0: 
michael@0:   this.getCurrentCell = function getCurrentCell()
michael@0:   {
michael@0:     var rowCount = this.table.rows.length;
michael@0:     var colsCount = this.getColsCount();
michael@0:     for (var rowIdx = 0; rowIdx < rowCount; rowIdx++) {
michael@0:       for (var colIdx = 0; colIdx < colsCount; colIdx++) {
michael@0:         var cell = this.table.rows[rowIdx].cells[colIdx];
michael@0:         if (cell.hasAttribute("tabindex"))
michael@0:           return cell;
michael@0:       }
michael@0:     }
michael@0:     return null;
michael@0:   }
michael@0: 
michael@0:   this.initGrid = function initGrid()
michael@0:   {
michael@0:     this.table.addEventListener("keypress", this, false);
michael@0:     this.table.addEventListener("click", this, false);
michael@0:   }
michael@0: 
michael@0:   this.handleEvent = function handleEvent(aEvent)
michael@0:   {
michael@0:     if (aEvent instanceof nsIDOMKeyEvent)
michael@0:       this.handleKeyEvent(aEvent);
michael@0:     else
michael@0:       this.handleClickEvent(aEvent);
michael@0:   }
michael@0: 
michael@0:   this.handleKeyEvent = function handleKeyEvent(aEvent)
michael@0:   {
michael@0:     if (aEvent.target.localName != "td")
michael@0:       return;
michael@0: 
michael@0:     var cell = aEvent.target;
michael@0:     switch(aEvent.keyCode) {
michael@0:       case nsIDOMKeyEvent.DOM_VK_UP:
michael@0:         var colsCount = this.getColsCount();
michael@0:         var idx = this.getIndexByCell(cell);
michael@0:         var upidx = idx - colsCount;
michael@0:         if (upidx >= 0) {
michael@0:           cell.removeAttribute("tabindex");
michael@0:           var upcell = this.getCellAtIndex(upidx);
michael@0:           upcell.setAttribute("tabindex", "0");
michael@0:           upcell.focus();
michael@0:         }
michael@0:         break;
michael@0: 
michael@0:       case nsIDOMKeyEvent.DOM_VK_DOWN:
michael@0:         var colsCount = this.getColsCount();
michael@0:         var idx = this.getIndexByCell(cell);
michael@0:         var downidx = idx + colsCount;
michael@0:         if (downidx <= this.getMaxIndex()) {
michael@0:           cell.removeAttribute("tabindex");
michael@0:           var downcell = this.getCellAtIndex(downidx);
michael@0:           downcell.setAttribute("tabindex", "0");
michael@0:           downcell.focus();
michael@0:         }
michael@0:         break;
michael@0: 
michael@0:       case nsIDOMKeyEvent.DOM_VK_LEFT:
michael@0:         var idx = this.getIndexByCell(cell);
michael@0:         if (idx > 0) {
michael@0:           cell.removeAttribute("tabindex");
michael@0:           var prevcell = this.getCellAtIndex(idx - 1);
michael@0:           prevcell.setAttribute("tabindex", "0");
michael@0:           prevcell.focus();
michael@0:         }
michael@0:         break;
michael@0: 
michael@0:       case nsIDOMKeyEvent.DOM_VK_RIGHT:
michael@0:         var idx = this.getIndexByCell(cell);
michael@0:         if (idx < this.getMaxIndex()) {
michael@0:           cell.removeAttribute("tabindex");
michael@0:           var nextcell = this.getCellAtIndex(idx + 1);
michael@0:           nextcell.setAttribute("tabindex", "0");
michael@0:           nextcell.focus();
michael@0:         }
michael@0:         break;
michael@0:     }
michael@0:   }
michael@0: 
michael@0:   this.handleClickEvent = function handleClickEvent(aEvent)
michael@0:   {
michael@0:     if (aEvent.target.localName != "td")
michael@0:       return;
michael@0:     
michael@0:     var curCell = this.getCurrentCell();
michael@0:     var cell = aEvent.target;
michael@0: 
michael@0:     if (cell != curCell) {
michael@0:       curCell.removeAttribute("tabindex");
michael@0:       cell.setAttribute("tabindex", "0");
michael@0:       cell.focus();
michael@0:     }
michael@0:   }
michael@0: 
michael@0:   this.table = getNode(aTableIdentifier);
michael@0:   this.initGrid();
michael@0: }