IBufferGraph::MapDownToFirstMatch Method (SnapshotPoint, PointTrackingMode, Predicate<ITextSnapshot^>^, PositionAffinity)

Visual Studio 2015

Maps a position in the graph to a position in a matching buffer that is lower in the graph. Source buffers are considered to be lower than the projection buffers that consume them.

Namespace: Microsoft.VisualStudio.Text.Projection
Assembly: Microsoft.VisualStudio.Text.Data (in Microsoft.VisualStudio.Text.Data.dll)

Syntax

C++

Nullable<SnapshotPoint> MapDownToFirstMatch(
	SnapshotPoint position,
	PointTrackingMode trackingMode,
	Predicate<ITextSnapshot^>^ match,
	PositionAffinity affinity
)

Parameters

position: Type: Microsoft.VisualStudio.Text::SnapshotPoint
The position in a buffer in the graph.

trackingMode: Type: Microsoft.VisualStudio.Text::PointTrackingMode
How position is tracked to the current snapshot if necessary.

match: Type: System::Predicate<ITextSnapshot^>^
The predicate that identifies the target buffer.

affinity

Type: Microsoft.VisualStudio.Text::PositionAffinity

If the mapping is ambiguous (the position is on a source span seam), determines whether the mapping should target the position immediately after the preceding character or immediately before the following character in the top buffer.

This setting has no effect if the mapping is unambiguous.

Return Value

Type: System::Nullable<SnapshotPoint>

A point in a snapshot of the target buffer, or null if position does not map down to any buffer selected by match.

Exceptions

Exception	Condition
ArgumentNullException	position.Snapshot or match is null.
ArgumentOutOfRangeException	trackingMode is not a valid PointTrackingMode, or affinity is not a valid PositionAffinity.

Remarks

The match predicate is called on each text buffer in the buffer graph until it returns true. After that the predicate is not called again.