IFormattable Interface
Definition
Important
Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.
The Formattable interface must be implemented by any class that
needs to perform custom formatting using the 's' conversion
specifier of java.util.Formatter.
[Android.Runtime.Register("java/util/Formattable", "", "Java.Util.IFormattableInvoker")]
public interface IFormattable : Android.Runtime.IJavaObject, IDisposable, Java.Interop.IJavaPeerable[<Android.Runtime.Register("java/util/Formattable", "", "Java.Util.IFormattableInvoker")>]
type IFormattable = interface
interface IJavaObject
interface IDisposable
interface IJavaPeerable- Attributes
- Implements
Remarks
The Formattable interface must be implemented by any class that needs to perform custom formatting using the 's' conversion specifier of java.util.Formatter. This interface allows basic control for formatting arbitrary objects.
For example, the following class prints out different representations of a stock's name depending on the flags and length constraints:
{@code
import java.nio.CharBuffer;
import java.util.Formatter;
import java.util.Formattable;
import java.util.Locale;
import static java.util.FormattableFlags.*;
...
public class StockName implements Formattable {
private String symbol, companyName, frenchCompanyName;
public StockName(String symbol, String companyName,
String frenchCompanyName) {
...
}
...
public void formatTo(Formatter fmt, int f, int width, int precision) {
StringBuilder sb = new StringBuilder();
// decide form of name
String name = companyName;
if (fmt.locale().equals(Locale.FRANCE))
name = frenchCompanyName;
boolean alternate = (f & ALTERNATE) == ALTERNATE;
boolean usesymbol = alternate || (precision != -1 && precision < 10);
String out = (usesymbol ? symbol : name);
// apply precision
if (precision == -1 || out.length() < precision) {
// write it all
sb.append(out);
} else {
sb.append(out.substring(0, precision - 1)).append('*');
}
// apply width and justification
int len = sb.length();
if (len < width)
for (int i = 0; i < width - len; i++)
if ((f & LEFT_JUSTIFY) == LEFT_JUSTIFY)
sb.append(' ');
else
sb.insert(0, ' ');
fmt.format(sb.toString());
}
public String toString() {
return String.format("%s - %s", symbol, companyName);
}
}
}
When used in conjunction with the java.util.Formatter, the above class produces the following output for various format strings.
{@code
Formatter fmt = new Formatter();
StockName sn = new StockName("HUGE", "Huge Fruit, Inc.",
"Fruit Titanesque, Inc.");
fmt.format("%s", sn); // -> "Huge Fruit, Inc."
fmt.format("%s", sn.toString()); // -> "HUGE - Huge Fruit, Inc."
fmt.format("%#s", sn); // -> "HUGE"
fmt.format("%-10.8s", sn); // -> "HUGE "
fmt.format("%.12s", sn); // -> "Huge Fruit,*"
fmt.format(Locale.FRANCE, "%25s", sn); // -> " Fruit Titanesque, Inc."
}
Formattables are not necessarily safe for multithreaded access. Thread safety is optional and may be enforced by classes that extend and implement this interface.
Unless otherwise specified, passing a null argument to any method in this interface will cause a NullPointerException to be thrown.
Added in 1.5.
Java documentation for java.util.Formattable.
Portions of this page are modifications based on work created and shared by the Android Open Source Project and used according to terms described in the Creative Commons 2.5 Attribution License.
Properties
| Handle |
Gets the JNI value of the underlying Android object. (Inherited from IJavaObject) |
| JniIdentityHashCode |
Returns the value of |
| JniManagedPeerState |
State of the managed peer. (Inherited from IJavaPeerable) |
| JniPeerMembers |
Member access and invocation support. (Inherited from IJavaPeerable) |
| PeerReference |
Returns a JniObjectReference of the wrapped Java object instance. (Inherited from IJavaPeerable) |
Methods
| Disposed() |
Called when the instance has been disposed. (Inherited from IJavaPeerable) |
| DisposeUnlessReferenced() |
If there are no outstanding references to this instance, then
calls |
| Finalized() |
Called when the instance has been finalized. (Inherited from IJavaPeerable) |
| FormatTo(Formatter, FormatFlags, Int32, Int32) |
Formats the object using the provided |
| SetJniIdentityHashCode(Int32) |
Set the value returned by |
| SetJniManagedPeerState(JniManagedPeerStates) | (Inherited from IJavaPeerable) |
| SetPeerReference(JniObjectReference) |
Set the value returned by |
| UnregisterFromRuntime() |
Unregister this instance so that the runtime will not return it from future Java.Interop.JniRuntime+JniValueManager.PeekValue invocations. (Inherited from IJavaPeerable) |
Extension Methods
| JavaCast<TResult>(IJavaObject) |
Performs an Android runtime-checked type conversion. |
| JavaCast<TResult>(IJavaObject) | |
| GetJniTypeName(IJavaPeerable) | |