Class NinePatch

Namespace

Egami.Drawing

Assembly

Egami.Drawing.dll

An image with its Lattice, as Android's nine-patch (.9.png) files hold them.

public sealed record NinePatch : IEquatable<NinePatch>

Inheritance

object

NinePatch

Implements

IEquatable<NinePatch>

Inherited Members

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.ReferenceEquals(object, object)

object.ToString()

Examples

using (RasterCanvas<Rgba8> canvas = raster.CreateCanvas())
{
    // An Android .9.png: its one-pixel border marks what stretches. The corners stay sharp at any size.
    (Raster inner, Lattice lattice, Rect? padding) = NinePatch.FromAndroid(file);
    canvas.DrawImageLattice(inner, lattice, new RectF(10, 10, 180, 48));
    inner.Dispose();

    // A nine-patch from a plain image: the 8-pixel corners keep their size, the edges and center stretch.
    canvas.DrawImageNinePatch(frame, new Rect(8, 8, 8, 8), new RectF(10, 70, 120, 40));

    // A lattice can leave cells out or fill them with a color: here the center becomes a flat panel.
    LatticeCellKind[] kinds = [.. Enumerable.Repeat(LatticeCellKind.Default, 9)];
    kinds[4] = LatticeCellKind.FixedColor;
    RgbaF32[] colors = new RgbaF32[9];
    colors[4] = new RgbaF32(0.95f, 0.95f, 0.9f, 1);
    canvas.DrawImageLattice(frame, new Lattice([8, 16], [8, 16]) { CellKinds = kinds, CellColors = colors }, new RectF(150, 70, 140, 40));
}

Constructors

NinePatch(Raster, Lattice, Rect?)

An image with its Lattice, as Android's nine-patch (.9.png) files hold them.

public NinePatch(Raster Image, Lattice Lattice, Rect? Padding)

Parameters

Image Raster

The image without its marker border.

Lattice Lattice

The stretchable columns and rows the markers set.

Padding Rect?

The content area the right and bottom markers set, in the image's pixels, or null when the file has none.

Examples

using (RasterCanvas<Rgba8> canvas = raster.CreateCanvas())
{
    // An Android .9.png: its one-pixel border marks what stretches. The corners stay sharp at any size.
    (Raster inner, Lattice lattice, Rect? padding) = NinePatch.FromAndroid(file);
    canvas.DrawImageLattice(inner, lattice, new RectF(10, 10, 180, 48));
    inner.Dispose();

    // A nine-patch from a plain image: the 8-pixel corners keep their size, the edges and center stretch.
    canvas.DrawImageNinePatch(frame, new Rect(8, 8, 8, 8), new RectF(10, 70, 120, 40));

    // A lattice can leave cells out or fill them with a color: here the center becomes a flat panel.
    LatticeCellKind[] kinds = [.. Enumerable.Repeat(LatticeCellKind.Default, 9)];
    kinds[4] = LatticeCellKind.FixedColor;
    RgbaF32[] colors = new RgbaF32[9];
    colors[4] = new RgbaF32(0.95f, 0.95f, 0.9f, 1);
    canvas.DrawImageLattice(frame, new Lattice([8, 16], [8, 16]) { CellKinds = kinds, CellColors = colors }, new RectF(150, 70, 140, 40));
}

Properties

Image

The image without its marker border.

public Raster Image { get; init; }

Property Value

Raster

Lattice

The stretchable columns and rows the markers set.

public Lattice Lattice { get; init; }

Property Value

Lattice

Padding

The content area the right and bottom markers set, in the image's pixels, or null when the file has none.

public Rect? Padding { get; init; }

Property Value

Rect?

Methods

FromAndroid(Raster)

Reads an Android nine-patch: the image has a one-pixel border whose opaque black pixels mark, on the top edge, the stretchable columns, on the left edge the stretchable rows, and on the right and bottom edges the content area. Other border pixels must be fully transparent, as Android requires.

public static NinePatch FromAndroid(Raster raster)

Parameters

raster Raster

The whole .9.png image, border included; its first frame is read.

Returns

NinePatch

The image inside the border, in the raster's pixel type, with its lattice and padding.

Examples

using (RasterCanvas<Rgba8> canvas = raster.CreateCanvas())
{
    // An Android .9.png: its one-pixel border marks what stretches. The corners stay sharp at any size.
    (Raster inner, Lattice lattice, Rect? padding) = NinePatch.FromAndroid(file);
    canvas.DrawImageLattice(inner, lattice, new RectF(10, 10, 180, 48));
    inner.Dispose();

    // A nine-patch from a plain image: the 8-pixel corners keep their size, the edges and center stretch.
    canvas.DrawImageNinePatch(frame, new Rect(8, 8, 8, 8), new RectF(10, 70, 120, 40));

    // A lattice can leave cells out or fill them with a color: here the center becomes a flat panel.
    LatticeCellKind[] kinds = [.. Enumerable.Repeat(LatticeCellKind.Default, 9)];
    kinds[4] = LatticeCellKind.FixedColor;
    RgbaF32[] colors = new RgbaF32[9];
    colors[4] = new RgbaF32(0.95f, 0.95f, 0.9f, 1);
    canvas.DrawImageLattice(frame, new Lattice([8, 16], [8, 16]) { CellKinds = kinds, CellColors = colors }, new RectF(150, 70, 140, 40));
}

Exceptions

ArgumentException

The image is smaller than 3×3, or a border pixel is neither opaque black nor transparent.