Package com.caplin.datasource.messaging.page

Interface PageMessage

All Superinterfaces:

Message

public interface PageMessage
extends Message

An instance of PageMessage represents updates to a Page subject.

An object implementing this interface cannot be instantiated directly, but can be constructed using the MessageFactory that is available on the Publisher interface.

Each update applies to a region of the page that starts at a specific column and row.

If you call setContent(int, int, String) more than once, and the page regions specified in successive calls overlap, the updates are still held separately in the message; they are not merged together.

Note: After publishing a message, do not reuse the message (e.g. change the content, republish) as this can cause issues.

Method Summary

Modifier and Type	Method	Description
void	clearFields()	Removes all the fields previously added to this PageMessage
boolean	containsField(java.lang.String fieldName)	Determines whether the message contains the specified field
java.lang.String	getField(java.lang.String fieldName)	Gets the value of the specified field.
java.util.List<Field>	getFields()	Gets the fields within this PageMessage, in the order of which the fields were sent.
int	getHeight()	Gets the height of the page, in text rows.
java.lang.String	getPageType()	Gets the type of the page.
java.util.List<PageElement>	getUpdatedElements()	Gets a read-only list of the updated page elements.
int	getWidth()	Gets the width of the page, in text columns.
void	removeField(java.lang.String fieldName)	Removes all occurrences given field from this PageMessage.
void	setContent(int column, int row, java.lang.String content)	Updates the contents of the page at the specified location.
void	setField(java.lang.String fieldName, java.lang.String value)	Sets a field value.
void	setHeight(int height)	Sets the height of the page, in text rows.
void	setPageType(java.lang.String pageType)	Sets the type of the page.
void	setWidth(int width)	Sets the width of the page, in text columns.

Methods inherited from interface com.caplin.datasource.messaging.Message

getMessageType, getSubject, isImage, setImage

Method Detail

setContent

void setContent(int column,
                int row,
                java.lang.String content)

Updates the contents of the page at the specified location.

Parameters:

column - The column at which the content is to be updated. The leftmost column of the page is column 0.

row - The row at which the content is to be updated. The top row of the page is row 0.

content - The page content to be placed at the specified row and column.

getWidth

int getWidth()

Gets the width of the page, in text columns.

This value is valid on all PageMessage instances created using the MessageFactory interface. However it may be undefined (and hence have a value of -1) on instances received by an implementation of SubscriptionListener

The first character on a page is at column zero. Therefore the maximum modifiable column is at position (Width - 1).

Returns:

The width of the page, in text columns.

setWidth

void setWidth(int width)

Sets the width of the page, in text columns.

This value is valid on all PageMessage instances created using the MessageFactory interface. However it may be undefined (and hence have a value of -1) on instances received by an implementation of SubscriptionListener.

The first character on a page is at column zero. Therefore the maximum modifiable column is at position (Width - 1).

Parameters:

width - The width of the page, in text columns.

getHeight

int getHeight()

Gets the height of the page, in text rows.

This value is valid on all PageMessage instances created using the MessageFactory interface, however it may be undefined (and hence have a value of -1) on instances received by an implementation of SubscriptionListener.

The first character on a page is at row zero. Therefore the maximum modifiable row is at position (height - 1).

Returns:

The height of the page, in text rows.

setHeight

void setHeight(int height)

Sets the height of the page, in text rows.

The first character on a page is at row zero. Therefore the maximum modifiable row is at row (height - 1).

Parameters:

height - The height of the page, in text rows.

getPageType

java.lang.String getPageType()

Gets the type of the page.

The type of the page is available to StreamLink clients and can be used to control the display of the page.

Returns:

The type of the page.

setPageType

void setPageType(java.lang.String pageType)

Sets the type of the page.

The type of the page is available to StreamLink clients and can be used to control the display of the page.

Parameters:

pageType - The type of the page.

getUpdatedElements

java.util.List<PageElement> getUpdatedElements()

Gets a read-only list of the updated page elements.

Returns:

The updated page elements.

clearFields

void clearFields()

Removes all the fields previously added to this PageMessage

containsField

boolean containsField(java.lang.String fieldName)

Determines whether the message contains the specified field

Parameters:

fieldName - Name of the field.

Returns:

true if the message contains the field, otherwise, false.

getFields

java.util.List<Field> getFields()

Gets the fields within this PageMessage, in the order of which the fields were sent. This can include duplicate field names for different values.

Returns:

A read-only list of the fields.

setField

void setField(java.lang.String fieldName,
              java.lang.String value)

Sets a field value.

If the field does not exist in this PageMessage, the field is added to it. Otherwise the existing occurrence of the field is updated to the new value.

Parameters:

fieldName - The name of the field.

value - The new value of the field.

Throws:

java.lang.IllegalArgumentException - Raised when the fieldName is not defined in the Fields configuration file.

getField

java.lang.String getField(java.lang.String fieldName)

Gets the value of the specified field. If the field does not exist in this PageMessage, null is returned.

Parameters:

fieldName - The name of the field to get.

Returns:

The value of the field with the name fieldName, or null if there is no such field in this PageMessage.

Throws:

java.lang.IllegalArgumentException - Raised when the fieldName is not defined in the Fields configuration file.

removeField

void removeField(java.lang.String fieldName)

Removes all occurrences given field from this PageMessage.

Parameters:

fieldName - The name of the field to remove.