Add Support For DataGrid DoubleTap Events Specific to the DataGridRows

[lukeblevins]

I'm submitting a...

• Feature request (UserVoice request: https://wpdev.uservoice.com/forums/110705-universal-windows-platform/suggestions/34576438-datagrid-doubletap-event-specific-to-the-datagridr ) -->

## Current behavior
Currently, to interact with a DataGrid's rows, you must specify a SelectionChanged event. This can become inefficient and somewhat confusing when users are able to select more than one items. Because of this, I would like the functionality to only execute the SelectedItem code when a row is DoubleTapped. Previously, it was possible to add an EventSetter to the DataGridRows' style (As mentioned here: https://stackoverflow.com/questions/22790181/wpf-datagrid-row-double-click-event-programmatically), but since EventSetter is now not apart of UWP, I am left without this functionality.

## Expected behavior
My proposed solution is to add a "RowDoubleTapped" event directly to the UWP DataGrid class itself. I need this to be easily accessible from my XAML code. This already exists with the ListView class which has a similar "ItemClicked" event as an alternative to SelectionChanged.

## Minimal reproduction of the problem with instructions
Create a project using a DataGrid (with a binded ItemSource) that requires DoubleTap event functionality on the DataGridRows themselves. The current DoubleTapped event is not row-specific, meaning it covers the entire DataGrid. I attempted to use this event only to find that the sender was returning a DataGrid rather than a DataGridRow.

Environment

``` Nuget Package(s): Microsoft.Toolkit.Uwp.UI.Controls.DataGrid

Package Version(s): 3.1.0-preview1 (LATEST as of 6/15/2018)

Windows 10 Build Number:

• Creators Update (15063)
• Fall Creators Update (16299)
• April 2018 Update (17134)
• Insider Build (build number: )

App min and target version:

• Creators Update (15063)
• Fall Creators Update (16299)
• April 2018 Update (17134)
• Insider Build (xxxxx)

Device form factor:

• Desktop
• Mobile
• Xbox
• Surface Hub
• IoT

Visual Studio

• 2017 (version: 15.7.3)
• 2017 Preview (version: )

[nmetulev]

ping @harinikmsft

[harinikmsft]

That seems like a valid ask, we might want to take a look at other DataGridRow** events that we may want to add as part of this. Marking this as a feature request for the future.

[robloo]

Duplicate of #2388

[robloo]

Definitely think a "RowPressed" and "RowDoublePressed" would be a big positive. This is not difficult to implement in the control either. Hoping this feature request is implemented in the next release.

As a bonus please consider "ColumnHeaderPressed" and "ColumnHeaderDoublePressed" as well

[lukeblevins]

Definitely think a "RowPressed" and "RowDoublePressed" would be a big positive. This is not difficult to implement in the control either. Hoping this feature request is implemented in the next release.
As a bonus please consider "ColumnHeaderPressed" and "ColumnHeaderDoublePressed" as well
I also think there needs to be a RowRightTapped to create a proper distinction between that and right-tapping the control itself. (Which should only include the column headers)

@robloo In the application I'm building, users currently have to manually select the row before right-clicking in order to display the row-appropriate context menu. Otherwise, it just displays the column header context menu. I think it would be more user-friendly to have a RowRightTapped which autoselects the nearest row and fires (all on rightclick).

[robloo]

@duke7553 I do the same thing in my application. When a right click is detected, I select the row under the click/press. A context menu is then displayed. Full code is below if this will help you :) For sure more of this should be 'out-of-the-box' functionality of the DataGrid.

I also think we need to stay away from the "Tapped" terminology -- this is specific for touch inputs. The generic "Pressed" is better for this I think.

View Code

private void DataGrid_PointerPressed(object sender, PointerRoutedEventArgs e)
{
	DataGrid dataGrid = sender as DataGrid;
	PointerPoint point = e.GetCurrentPoint(dataGrid);
	DataGridRow pressedRow = null;
	object pressedObject = null;
	MenuFlyout flyout;

	// Determine the pressed row
	try
	{
		pressedRow    = FindParent<DataGridRow>(e.OriginalSource as DependencyObject);
		pressedObject = ((List<object>)dataGrid.ItemsSource)[pressedRow.GetIndex()];
	}
	catch { }

	if (point.Properties.IsRightButtonPressed)
	{
		// Select the row
		try
		{
			dataGrid.SelectedItems.Clear();
			dataGrid.SelectedItems.Add(pressedObject);
		}
		catch { }

		// Open the context menu flyout
		try
		{
			flyout = new MenuFlyout(); // Do other stuff here
			flyout.ShowAt(dataGrid, point.Position);
		}
		catch { }
	}
	else
	{
		// Do other stuff
	}

	return;
}

/// <summary>
/// Finds the parent element of the specified type.
/// </summary>
/// <typeparam name="T">The type of the parent element to return.</typeparam>
/// <param name="child">The child to find the element for.</param>
/// <returns></returns>
public static T FindParent<T>(DependencyObject child) where T : DependencyObject
{
	T parent = null;
	DependencyObject currParent;

	currParent = VisualTreeHelper.GetParent(child);
	while (currParent != null)
	{
	   if (currParent is T)
	   {
		  parent = (T)currParent;
		  break;
	   }

	   // find the next parent
	   currParent = VisualTreeHelper.GetParent(currParent);
	}

	return (parent);
}

[lukeblevins]

@robloo Thank you for this code! I agree, this should be implemented out-of-the-box within DataGrid.

[robloo]

Since @harinikmsft was collecting a list of events that we may want to add for this, I have summarized as follows:

• RowPressed : As discussed above. Indicates a row has been pressed so further processing or context menu's can occur.
• RowDoublePressed : Same as RowPressed, just the double click version.
• ColumnHeaderPressed : Occurs whenever a column header is pressed. Must take priority over any sort direction internal updates. This will allow for custom filtering menus or right click options to turn on/off columns.
• ColumnHeaderDoublePressed : Same as ColumnHeaderPressed, just the double click version.
• ColumnHeaderWidthChanged : Occurs whenever the user resizes a column header width. This will allow for saving this information in a clean way. This is commonly needed when restoring UI state.

[anawishnoff]

We are not adding features to this DataGrid at this time. I know you already added some feedback along these lines to the WinUI discussion issue - feel free to add more if anything comes up. Thanks!

[Kyaa-dost]

Closing this request since these features are not being added at this time.