Package icyllis.modernui.graphics.text

Class LayoutCache

java.lang.Object

icyllis.modernui.graphics.text.LayoutCache

@ThreadSafe
public final class LayoutCache
extends Object

Globally shared layout cache. Useful when recycling layouts, or raw data source and layout information are separated. Max memory usage: 7~10 MB.

Since:

2.6

See Also:

• LayoutPiece

Field Summary

Fields

Modifier and Type	Field	Description
static final int	COMPUTE_CLUSTER_ADVANCES	Also computes per-cluster advances.
static final int	COMPUTE_GLYPHS_PIXEL_BOUNDS	Also computes total pixel bounds of all glyph images.
static final int	MAX_PIECE_LENGTH	The internal policy on the maximum length of a text run, shared globally.

Constructor Summary

Constructors

Constructor	Description
LayoutCache()

Method Summary

Modifier and Type	Method	Description
static void	clear()	Clear the cache.
static int	getMemoryUsage()	This only returns measurable memory usage, in other words, at least
static LayoutPiece	getOrCreate(char[] buf, int contextStart, int contextLimit, int start, int limit, boolean isRtl, FontPaint paint, int computeFlags)	Get or create the layout piece from the global cache with given requirements.
static int	getSize()	Returns the approximate number of entries in this cache.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

MAX_PIECE_LENGTH

public static final int MAX_PIECE_LENGTH

The internal policy on the maximum length of a text run, shared globally.

See Also:

• Constant Field Values

COMPUTE_CLUSTER_ADVANCES

public static final int COMPUTE_CLUSTER_ADVANCES

Also computes per-cluster advances.

See Also:

• LayoutPiece.getAdvances()
• Constant Field Values

COMPUTE_GLYPHS_PIXEL_BOUNDS

public static final int COMPUTE_GLYPHS_PIXEL_BOUNDS

Also computes total pixel bounds of all glyph images.

See Also:

• LayoutPiece.getBoundsX()
• LayoutPiece.getBoundsY()
• Constant Field Values

Constructor Details

LayoutCache

public LayoutCache()

Method Details

getOrCreate

@NonNull
public static LayoutPiece getOrCreate(@NonNull
 char[] buf,
 int contextStart,
 int contextLimit,
 int start,
 int limit,
 boolean isRtl,
 @NonNull
 FontPaint paint,
 int computeFlags)

Get or create the layout piece from the global cache with given requirements.

In particular, the given range cannot exceed MAX_PIECE_LENGTH to increase the reuse rate of pieced text. The given text must be in the same paragraph and should not break the grapheme cluster.

Use computeFlags to compute optional info lazily.

Parameters:

buf - text buffer, cannot be null or empty, only referred in stack

start - start char offset

limit - end char index

isRtl - whether to layout in right-to-left

paint - the font paint affecting measurement

computeFlags - additional desired info to compute, or 0

Returns:

the layout piece

getSize

public static int getSize()

Returns the approximate number of entries in this cache.

getMemoryUsage

public static int getMemoryUsage()

This only returns measurable memory usage, in other words, at least

Returns:

memory usage in bytes

clear

public static void clear()

Clear the cache.