If you have not read the previous posts, you might want to start from the
first post.
We have discussed the
DataSource in previous post, we will continue discussion on the DataGrid.column in this post. Just a re-cap, we have following codes in previous post. DataGrid.column is parameter to
DataGrid.addColumnStyle() as shown below.
DataGrid.setNoDataText("No data available");
DataGrid.addColumnStyle(new cls_datagrid.column("Header 1", "header_5", 50));
DataGrid.addColumnStyle(new cls_datagrid.column("Header 2", "header_4", 80));
DataGrid.addColumnStyle(new cls_datagrid.column("Header 3", "header_3", 130));
DataGrid.addColumnStyle(new cls_datagrid.column("Header 4", "header_2", 120));
DataGrid.addColumnStyle(new cls_datagrid.column("Header 5", "header_1", 80));
DataGrid.addColumnStyle(new cls_datagrid.column("Header 6", "header_0", 140));
DataGrid.setDataSource(DataSource);
DataGrid.refresh();
DataGrid.column is a static class in DataGrid class. As you might notice, column is a very simple class with getter and setter methods.
public static class column{
private String strColumnName;
private String strFieldName;
private int intWidth;
private int intIndex;
public column(String DisplayName, String FieldName, int width)
{
strColumnName = DisplayName;
strFieldName = FieldName;
intWidth = width;
}
public void setIndex(int index)
{
intIndex = index;
}
public int getIndex()
{
return intIndex;
}
public String getColumnName()
{
return strColumnName;
}
public String getFieldName()
{
return strFieldName;
}
public int getWitdh()
{
return intWidth;
}
public void setWidth(int width){
intWidth = width;
}
}
Let's examine the class DataGrid, finally. :)
public class cls_datagrid extends LinearLayout{
private Context mContext;
private members_collection mc;
private String strNoDataText;
class members_collection{
public ArrayList<column> COLUMN_STYLE;
}
public static class column{
private String strColumnName;
private String strFieldName;
private int intWidth;
private int intIndex;
public column(String DisplayName, String FieldName, int width)
{
strColumnName = DisplayName;
strFieldName = FieldName;
intWidth = width;
}
public void setIndex(int index)
{
intIndex = index;
}
public int getIndex()
{
return intIndex;
}
public String getColumnName()
{
return strColumnName;
}
public String getFieldName()
{
return strFieldName;
}
public int getWitdh()
{
return intWidth;
}
public void setWidth(int width){
intWidth = width;
}
}
public cls_datagrid(Context context , AttributeSet attrs) throws Exception {
super(context, attrs);
setOrientation(VERTICAL);
mContext = context;
mc = new members_collection();
mc.COLUMN_STYLE = new ArrayList<column>();
}
public void addColumnStyle(column columnStyle)
{
mc.COLUMN_STYLE.add(columnStyle);
}
public void setNoDataText(String strText)
{
strNoDataText = strText;
}
}
Couple of things to note here.
- DataGrid extends LinearLayout
- member_collection class is just a placeholder to hold variables that to be shared amongst all the classes in the package.
- In the construction, we initialize the columns as an ArrayList and assign it to mc.COLUMN_STYLE
- function addColumnStyle(column) simply take DataGrid.column and put it in the ArrayList
- setNoDataText() is used to assign string value to display for an empty DataGrid
So we have an incomplete DataGrid class for now which has only DataGrid.column feature.
Next,
DataGrid Part 4 - DataGrid Header
The first thing to construct in DataGrid and it is also the part to be discussed in this post is the DataGrid header. As you might recall the screen of the DataGrid in the very first post as shown on the left.
