Wednesday, April 13, 2016

Need to Synchronize Columns of a Master/Detail Grid in DevEx WPF?

I generally prefer Telerik controls, but I've got a client that uses Developer Express.  I recently had a need to synchronize columns in a Developer Express WPF Master/Detail grid.   It's a bit of an unusual circumstance, where we have Master / Detail records that use the same view interface, but found the TreeListControl unable to scale up to the demands of our use cases.  The client still wanted the detail grid's columns to appear to functionally be the same column as the master record's (with the ability to show/hide the detail).

Thankfully, the Dev Express GridColumn class is a DependencyObject, and all the needed properties are exposed as DependencyProperty's.

Since the detail grid has the same data interface as the master grid, I was even able to clone the column definitions. 

Finally, since this was an MVVM project, I didn't want the functionality in code-behind, so I abstracted the code for this into a Behavior.

The approach was to bind the Width, Visibility, and VisibleIndex properties of each master grid column to a cloned detail grid column, giving the two entities the appearance of being one functional entity.
Here's the snippet representing the detail grid definition....




        <dxg:GridControl>


<!-- Master grid defined here, not shown.  Detail grid below   -->



          <dxg:GridControl.DetailDescriptor>


                <dxg:DataControlDetailDescriptor ItemsSourceBinding="{Binding Details}">


                    <dxg:GridControl x:Name="DetailsGrid" AutoGenerateColumns="None" ColumnsSource="{StaticResource ColumnsCollection}" >


                        <dxg:GridControl.View    >





                            <dxg:TableView  AutoWidth="False"


                            AllowCascadeUpdate="False"

                            AllowFixedGroups="True"

                            ShowGroupPanel="False"

                            CellStyle="{StaticResource DefaultCellStyle}"

                            NavigationStyle="Row"

                            ShowGroupedColumns="True"

                            AllowGrouping="True"

                            AllowEditing="False"

                            AllowScrollAnimation="False"

                            ShowFixedTotalSummary="False"

                            AllowHorizontalScrollingVirtualization="True"

                            HorizontalScrollbarVisibility="Auto"

                            RowStyle="{StaticResource RowStyle}"

                            AlternateRowBackground="{x:Static dxRes:DevExpressResources.AlternateRowBackgroundBrush}"

                            UseLightweightTemplates="None"

                            ShowColumnHeaders="False"

                               />

                        </dxg:GridControl.View>

                        <i:Interaction.Behaviors>


                            <local:SyncDetailGridColumnsBehavior/>


                        </i:Interaction.Behaviors>

                    </dxg:GridControl>

                </dxg:DataControlDetailDescriptor>

            </dxg:GridControl.DetailDescriptor>

        </dxg:GridControl>


Note the highlighted part above that introduces a local class called SyncDetailGridColumsBehavior, shown in its entirety below:




using System.Windows.Data;


using System.Windows.Interactivity;


using DevExpress.Xpf.Grid;


namespace Local
{
    public class SyncDetailGridColumnsBehavior : Behavior<GridControl>
    {
        private GridColumnCollection _parentGridColumns;
        private GridColumnCollection _detailsGridColumns;

        protected override void OnAttached()
        {
            _detailsGridColumns = AssociatedObject.Columns;
            _parentGridColumns = AssociatedObject.ResolveParentColumnCollection();
            InitializeMasterDetailGrid();
        }
       
        private void InitializeMasterDetailGrid()
        {
            _detailsGridColumns.CloneColumnsAndBindWidthsFrom(_parentGridColumns);
        }
    }

    internal static class ColumnHelpers
    {

        public static GridColumnCollection ResolveParentColumnCollection(this GridControl associatedObject)
        {
            var result =
                ((DevExpress.Xpf.Grid.GridControl)
                    ((System.Windows.FrameworkContentElement) associatedObject.Parent).Parent).Columns;
            return result;
        }

        public static void CloneColumnsAndBindWidthsFrom(this GridColumnCollection targetGridColumns,
            GridColumnCollection sourceGrid)
        {
            targetGridColumns.Clear();
            foreach (var aSourceColumn in sourceGrid)
            {
                var aClonedColumn = aSourceColumn.Clone();
                aSourceColumn.BindWidths(aClonedColumn);
                aSourceColumn.BindPositions(aClonedColumn);
                targetGridColumns.Add(aClonedColumn);
            }
        }

        public static GridColumn Clone(this GridColumn source)
        {
            return new GridColumn()
            {
                Name = source.Name,
                Width = source.Width,
                Binding = source.Binding,
                Header = source.Header,
                Style = source.Style,
                CellStyle = source.CellStyle,
                CellTemplateSelector = source.CellTemplateSelector,
                CellTemplate = source.CellTemplate,
               
            };
        }

        public static void BindWidths(this GridColumn source, GridColumn bindingPartner)
        {
            source.SetBinding(BaseColumn.WidthProperty,
                new Binding("ActualWidth")
                {
                    Source = bindingPartner,
                    Mode = BindingMode.OneWay,
                    UpdateSourceTrigger = UpdateSourceTrigger.PropertyChanged
                });
            bindingPartner.SetBinding(BaseColumn.WidthProperty,
                new Binding("ActualWidth")
                {
                    Source = source,
                    Mode = BindingMode.OneWay,
                    UpdateSourceTrigger = UpdateSourceTrigger.PropertyChanged
                });
        }

        public static void BindPositions(this GridColumn source, GridColumn bindingPartner)
        {
            source.SetBinding(BaseColumn.VisibleIndexProperty,
                new Binding("VisibleIndex")
                {
                    Source = bindingPartner,
                    Mode = BindingMode.TwoWay,
                    UpdateSourceTrigger = UpdateSourceTrigger.PropertyChanged
                });
           
        }

        public static void BindVisibility(this GridColumn source, GridColumn bindingPartner)
        {
            source.SetBinding(BaseColumn.VisibleProperty,
                new Binding("Visible")
                {
                    Source = bindingPartner,
                    Mode = BindingMode.TwoWay,
                    UpdateSourceTrigger = UpdateSourceTrigger.PropertyChanged
                });

        }
    }
}

       
I expect this to cover 90% of our needs, the other 10% has to do with row selection across master/detail boundaries, but that's a story for another day.

In the meantime, let me know how this makes ya feel...  leave a comment, below.

Thanks!

Sunday, April 10, 2016

Rise of the Smart App

Microsoft didn't talk much about the Windows Phone at Build 2016.  If you think that's news, you're missing the point.

As Microsoft re-defines "Mobile First, Cloud First" they declare shenanigans on the idea that the tech world revolves around phone and tablet.  Yes, tablet and smartphone are mature, first-class citizens, now, but they're not above laptops, PCs, or other computing devices, as Apple (and perhaps even Samsung) might have you believe.

There's no denying that Microsoft lost the battle for smartphone market share.  RIM's Blackberry, considered a relic of the primordial smartphone market, is all but forgotten. Microsoft was pushing Windows Phone as significant competitor, yet, with about the same market share as Blackberry, no one really took their smartphone offering seriously. 

Until Windows Phone's recent convergence with the PC on the universal Windows 10 OS, Windows Phone had no more competitive edge than Blackberry, either.  Sadly, this new competitive edge comes too little, too late. Or has it?

Several years ago, in a very sly move, Apple narrowed and laser-focused the global technology mindset on a much smaller battle... one that it was well positioned in. Apple then equated the battle to the war... They made it all about the smartphone/tablet market.  (I don't think Apple counted on Android, but it didn't matter... in terms of market share, Android won, but in terms of profitability, Apple won.)  Billions of dollars can't be wrong, so Microsoft tried to position itself in Apple's vision, and let itself get dragged around for years... 

Until now.

By connecting Mobility with Portability, Microsoft is driving the scope of technology mindshare again, and are driving it back out to a scale Apple will have to struggle to position itself in. Apple made good smartphones.  Cool beans.

With its converged "Universal" Windows 10 platform, Xamarin portability, and mature cloud offerings replete with machine learning, Microsoft is targeting a much broader "smart app" market... Smart Apps are apps that make any device (keyboard, mouse, display/touchscreen, microphone, pen, scanner, camera, video recorder/editor, audio mixer, cell phone, media player, whiteboard, virtual/augmented reality, what have you) into a smart device.  (Notice anything missing here?  perhaps cars...  but it's hard to imagine that won't change in the next few years...  after all, cars (e.g. BMW) did get mentioned at Build.) 

The smartphone isn't irrelevant, it's just not the whole pie. The reality is that Microsoft is not going to exclude phones from Windows 10 now or any time soon. 

Smartphone prominence is not innovation superiority.

So, how does this make you feel?