scim 1.4.18
scim::IMEngineInstanceBase Class Referenceabstract

The base class of the real input methods' IMEngineInstance classes. More...

#include <scim_imengine.h>

Public Member Functions

 IMEngineInstanceBase (IMEngineFactoryBase *factory, const String &encoding, int id=-1)
 Constructor.
 
virtual ~IMEngineInstanceBase ()
 Virtual destructor.
 
virtual bool set_encoding (const String &encoding)
 Set the working encoding for this instance.
 
String get_encoding () const
 Get the working encoding of this instance.
 
int get_id () const
 Get the unique id of this instance.
 
String get_factory_uuid () const
 Get the UUID of the engine factory.
 
void set_frontend_data (void *data)
 Attach a pointer to this IMEngineInstance, which is pointed to corresponding FrontEnd data.
 
voidget_frontend_data (void)
 Retrieve the pointer previously attached by set_frontend_data();.
 
Signal connection functions.

These functions are used by FrontEnds to connect their corresponding slots to this IMEngineInstance's signals.

Connection signal_connect_show_preedit_string (IMEngineSlotVoid *slot)
 
Connection signal_connect_show_aux_string (IMEngineSlotVoid *slot)
 
Connection signal_connect_show_lookup_table (IMEngineSlotVoid *slot)
 
Connection signal_connect_hide_preedit_string (IMEngineSlotVoid *slot)
 
Connection signal_connect_hide_aux_string (IMEngineSlotVoid *slot)
 
Connection signal_connect_hide_lookup_table (IMEngineSlotVoid *slot)
 
Connection signal_connect_update_preedit_caret (IMEngineSlotInt *slot)
 
Connection signal_connect_update_preedit_string (IMEngineSlotWideStringAttributeList *slot)
 
Connection signal_connect_update_aux_string (IMEngineSlotWideStringAttributeList *slot)
 
Connection signal_connect_update_lookup_table (IMEngineSlotLookupTable *slot)
 
Connection signal_connect_commit_string (IMEngineSlotWideString *slot)
 
Connection signal_connect_forward_key_event (IMEngineSlotKeyEvent *slot)
 
Connection signal_connect_register_properties (IMEngineSlotPropertyList *slot)
 
Connection signal_connect_update_property (IMEngineSlotProperty *slot)
 
Connection signal_connect_beep (IMEngineSlotVoid *slot)
 
Connection signal_connect_start_helper (IMEngineSlotString *slot)
 
Connection signal_connect_stop_helper (IMEngineSlotString *slot)
 
Connection signal_connect_send_helper_event (IMEngineSlotStringTransaction *slot)
 
Connection signal_connect_get_surrounding_text (IMEngineSlotGetSurroundingText *slot)
 
Connection signal_connect_delete_surrounding_text (IMEngineSlotDeleteSurroundingText *slot)
 
Action functions.

These functions will be called by FrontEnds to send events to this IMEngineInstance.

virtual bool process_key_event (const KeyEvent &key)=0
 Process a key event.
 
virtual void move_preedit_caret (unsigned int pos)
 Move the preedit caret in the preedit string.
 
virtual void select_candidate (unsigned int index)
 Select a candidate in current lookup table.
 
virtual void update_lookup_table_page_size (unsigned int page_size)
 Update the page size of current lookup table.
 
virtual void lookup_table_page_up ()
 Flip the lookup table to the previous page.
 
virtual void lookup_table_page_down ()
 Flip the lookup table to the next page.
 
virtual void reset ()
 Reset this engine instance.
 
virtual void focus_in ()
 Focus in this engine instance.
 
virtual void focus_out ()
 Focus out this engine instance.
 
virtual void trigger_property (const String &property)
 Trigger a property.
 
virtual void process_helper_event (const String &helper_uuid, const Transaction &trans)
 Process the events sent from a Client Helper process.
 
virtual void update_client_capabilities (unsigned int cap)
 Update the capabilities of current client application which is attached to this IMEngineInstance.
 
- Public Member Functions inherited from scim::ReferencedObject
bool is_referenced () const
 
void ref ()
 Increase an object's reference count by one.
 
void unref ()
 

Protected Member Functions

Signal activation functions

These functions should be called by derived classes to fire the corresponding signals. The FrontEnd connected to those signals will receive and process them.

void show_preedit_string ()
 Show the preedit string area.
 
void show_aux_string ()
 Show the aux string area.
 
void show_lookup_table ()
 Show the lookup table area.
 
void hide_preedit_string ()
 Hide the preedit string area.
 
void hide_aux_string ()
 Hide the aux string area.
 
void hide_lookup_table ()
 Hide the lookup table area.
 
void update_preedit_caret (int caret)
 Update the preedit caret position in the preedit string.
 
void update_preedit_string (const WideString &str, const AttributeList &attrs=AttributeList())
 Update the content of the preedit string,.
 
void update_aux_string (const WideString &str, const AttributeList &attrs=AttributeList())
 Update the content of the aux string,.
 
void update_lookup_table (const LookupTable &table)
 Update the content of the lookup table,.
 
void commit_string (const WideString &str)
 Commit a string to the client application.
 
void forward_key_event (const KeyEvent &key)
 Forward a key event to the client application.
 
void register_properties (const PropertyList &properties)
 Register all properties of this IMEngineInstance into the FrontEnd.
 
void update_property (const Property &property)
 Update a registered property.
 
void beep ()
 Generate a short beep.
 
void start_helper (const String &helper_uuid)
 Start a Client Helper process.
 
void stop_helper (const String &helper_uuid)
 Stop a Client Helper process which was started by start_helper.
 
void send_helper_event (const String &helper_uuid, const Transaction &trans)
 Send an events transaction to a client helper process.
 
bool get_surrounding_text (WideString &text, int &cursor, int maxlen_before=-1, int maxlen_after=-1)
 Retrieves context around the insertion point.
 
bool delete_surrounding_text (int offset, int len)
 Ask the client to delete characters around the cursor position.
 
- Protected Member Functions inherited from scim::ReferencedObject
 ReferencedObject ()
 Constructor.
 
virtual ~ReferencedObject ()=0
 Destructor.
 
void set_referenced (bool reference)
 

Detailed Description

The base class of the real input methods' IMEngineInstance classes.

Each input method should implement a class derived from scim::IMEngineInstanceBase, which takes charge of recording Input Context status and processing user input events.

Constructor & Destructor Documentation

◆ IMEngineInstanceBase()

scim::IMEngineInstanceBase::IMEngineInstanceBase ( IMEngineFactoryBase * factory,
const String & encoding,
int id = -1 )

Constructor.

Parameters
factory- the factory which creates this instance.
encoding- the working encoding.
id- the unique id of this instance.

◆ ~IMEngineInstanceBase()

virtual scim::IMEngineInstanceBase::~IMEngineInstanceBase ( )
virtual

Virtual destructor.

Member Function Documentation

◆ set_encoding()

virtual bool scim::IMEngineInstanceBase::set_encoding ( const String & encoding)
virtual

Set the working encoding for this instance.

One engine instance can only support one client encoding at the same time. This encoding must be supported by the IMEngineFactory as well.

This method could be overrided in derived class to do some extra job. But the method of this base class must be invoked within the new method.

After invoking this method, reset() should be invoked to let the new encoding take effect.

Returns
true if the encoding is supported, otherwise false.

Reimplemented in scim::FilterInstanceBase.

◆ get_encoding()

String scim::IMEngineInstanceBase::get_encoding ( ) const

Get the working encoding of this instance.

This method returns the encoding passed to the constructor when constructing this object.

Returns
The working encoding.

◆ get_id()

int scim::IMEngineInstanceBase::get_id ( ) const

Get the unique id of this instance.

Returns
The id of this instance.

◆ get_factory_uuid()

String scim::IMEngineInstanceBase::get_factory_uuid ( ) const

Get the UUID of the engine factory.

Returns
The UUID string of the engine factory.

◆ set_frontend_data()

void scim::IMEngineInstanceBase::set_frontend_data ( void * data)

Attach a pointer to this IMEngineInstance, which is pointed to corresponding FrontEnd data.

Parameters
dataThe pointer to corresponding FrontEnd data, eg. input context object.

◆ get_frontend_data()

void * scim::IMEngineInstanceBase::get_frontend_data ( void )

Retrieve the pointer previously attached by set_frontend_data();.

Returns
The pointer previously attached by set_frontend_data();

◆ signal_connect_show_preedit_string()

Connection scim::IMEngineInstanceBase::signal_connect_show_preedit_string ( IMEngineSlotVoid * slot)

◆ signal_connect_show_aux_string()

Connection scim::IMEngineInstanceBase::signal_connect_show_aux_string ( IMEngineSlotVoid * slot)

◆ signal_connect_show_lookup_table()

Connection scim::IMEngineInstanceBase::signal_connect_show_lookup_table ( IMEngineSlotVoid * slot)

◆ signal_connect_hide_preedit_string()

Connection scim::IMEngineInstanceBase::signal_connect_hide_preedit_string ( IMEngineSlotVoid * slot)

◆ signal_connect_hide_aux_string()

Connection scim::IMEngineInstanceBase::signal_connect_hide_aux_string ( IMEngineSlotVoid * slot)

◆ signal_connect_hide_lookup_table()

Connection scim::IMEngineInstanceBase::signal_connect_hide_lookup_table ( IMEngineSlotVoid * slot)

◆ signal_connect_update_preedit_caret()

Connection scim::IMEngineInstanceBase::signal_connect_update_preedit_caret ( IMEngineSlotInt * slot)

◆ signal_connect_update_preedit_string()

Connection scim::IMEngineInstanceBase::signal_connect_update_preedit_string ( IMEngineSlotWideStringAttributeList * slot)

◆ signal_connect_update_aux_string()

Connection scim::IMEngineInstanceBase::signal_connect_update_aux_string ( IMEngineSlotWideStringAttributeList * slot)

◆ signal_connect_update_lookup_table()

Connection scim::IMEngineInstanceBase::signal_connect_update_lookup_table ( IMEngineSlotLookupTable * slot)

◆ signal_connect_commit_string()

Connection scim::IMEngineInstanceBase::signal_connect_commit_string ( IMEngineSlotWideString * slot)

◆ signal_connect_forward_key_event()

Connection scim::IMEngineInstanceBase::signal_connect_forward_key_event ( IMEngineSlotKeyEvent * slot)

◆ signal_connect_register_properties()

Connection scim::IMEngineInstanceBase::signal_connect_register_properties ( IMEngineSlotPropertyList * slot)

◆ signal_connect_update_property()

Connection scim::IMEngineInstanceBase::signal_connect_update_property ( IMEngineSlotProperty * slot)

◆ signal_connect_beep()

Connection scim::IMEngineInstanceBase::signal_connect_beep ( IMEngineSlotVoid * slot)

◆ signal_connect_start_helper()

Connection scim::IMEngineInstanceBase::signal_connect_start_helper ( IMEngineSlotString * slot)

◆ signal_connect_stop_helper()

Connection scim::IMEngineInstanceBase::signal_connect_stop_helper ( IMEngineSlotString * slot)

◆ signal_connect_send_helper_event()

Connection scim::IMEngineInstanceBase::signal_connect_send_helper_event ( IMEngineSlotStringTransaction * slot)

◆ signal_connect_get_surrounding_text()

Connection scim::IMEngineInstanceBase::signal_connect_get_surrounding_text ( IMEngineSlotGetSurroundingText * slot)

◆ signal_connect_delete_surrounding_text()

Connection scim::IMEngineInstanceBase::signal_connect_delete_surrounding_text ( IMEngineSlotDeleteSurroundingText * slot)

◆ process_key_event()

virtual bool scim::IMEngineInstanceBase::process_key_event ( const KeyEvent & key)
pure virtual

Process a key event.

Parameters
key- the key event to be processed.
Returns
true if the event is processed, otherwise the event is not processed and should be forward to client application.

Implemented in scim::ComposeKeyInstance, scim::FilterInstanceBase, and scim::DummyIMEngineInstance.

◆ move_preedit_caret()

virtual void scim::IMEngineInstanceBase::move_preedit_caret ( unsigned int pos)
virtual

Move the preedit caret in the preedit string.

Parameters
pos- the new position that user requested.

Reimplemented in scim::ComposeKeyInstance, and scim::FilterInstanceBase.

◆ select_candidate()

virtual void scim::IMEngineInstanceBase::select_candidate ( unsigned int index)
virtual

Select a candidate in current lookup table.

When user click a candidate directly, this method will be invoked by FrontEnd.

Parameters
index- the index in current page of the selected candidate.

Reimplemented in scim::ComposeKeyInstance, and scim::FilterInstanceBase.

◆ update_lookup_table_page_size()

virtual void scim::IMEngineInstanceBase::update_lookup_table_page_size ( unsigned int page_size)
virtual

Update the page size of current lookup table.

In the next time, the lookup table should page down by this size.

Parameters
page_size- the new size of current page.

Reimplemented in scim::ComposeKeyInstance, and scim::FilterInstanceBase.

◆ lookup_table_page_up()

virtual void scim::IMEngineInstanceBase::lookup_table_page_up ( )
virtual

Flip the lookup table to the previous page.

The method will be invoked by FrontEnd when user click the lookup table page up button.

Reimplemented in scim::ComposeKeyInstance, and scim::FilterInstanceBase.

◆ lookup_table_page_down()

virtual void scim::IMEngineInstanceBase::lookup_table_page_down ( )
virtual

Flip the lookup table to the next page.

The method will be invoked by FrontEnd when user click the lookup table page down button.

Reimplemented in scim::ComposeKeyInstance, and scim::FilterInstanceBase.

◆ reset()

virtual void scim::IMEngineInstanceBase::reset ( )
virtual

Reset this engine instance.

All status of this engine instance should be reset, including the working encoding.

The client encoding may have been changed before calling this method, so if the IMEngine makes use of the client's encoding information, it should check whether the encoding has been changed. IMEngineInstance could call the get_encoding () method of base class to get the client encoding.

Reimplemented in scim::ComposeKeyInstance, and scim::FilterInstanceBase.

◆ focus_in()

virtual void scim::IMEngineInstanceBase::focus_in ( )
virtual

Focus in this engine instance.

This function should update/show/hide the status area, preedit area and lookup table, and update the full width punctuation/letter state.

Reimplemented in scim::ComposeKeyInstance, scim::FilterInstanceBase, and scim::DummyIMEngineInstance.

◆ focus_out()

virtual void scim::IMEngineInstanceBase::focus_out ( )
virtual

Focus out this engine instance.

Reimplemented in scim::ComposeKeyInstance, and scim::FilterInstanceBase.

◆ trigger_property()

virtual void scim::IMEngineInstanceBase::trigger_property ( const String & property)
virtual

Trigger a property.

This function should do some action according to the triggered property. For example toggle the input mode, etc.

Parameters
propertythe key of the triggered property.

Reimplemented in scim::ComposeKeyInstance, and scim::FilterInstanceBase.

◆ process_helper_event()

virtual void scim::IMEngineInstanceBase::process_helper_event ( const String & helper_uuid,
const Transaction & trans )
virtual

Process the events sent from a Client Helper process.

Parameters
helper_uuidThe UUID of the Helper process which sent the events.
transThe transaction which contains the events.

Reimplemented in scim::FilterInstanceBase.

◆ update_client_capabilities()

virtual void scim::IMEngineInstanceBase::update_client_capabilities ( unsigned int cap)
virtual

Update the capabilities of current client application which is attached to this IMEngineInstance.

Some client may not support all capabilities provided by the IMEngine API. For example:

  • OnTheSpot preedit string display (Embedded into client window).
  • Property display
  • Helper module
  • etc.

This method will be called to inform this IMEngineInstance object which capabilities are supported by the client application. It may be called multiple times, if the capabilities was changed.

Parameters
capA bitmask to indicate which client capabilities are supported by the client application.
See also
scim::ClientCapability

Reimplemented in scim::FilterInstanceBase.

◆ show_preedit_string()

void scim::IMEngineInstanceBase::show_preedit_string ( )
protected

Show the preedit string area.

The preedit string should be updated by calling update_preedit_string before or right after this call.

◆ show_aux_string()

void scim::IMEngineInstanceBase::show_aux_string ( )
protected

Show the aux string area.

The aux string should be updated by calling update_aux_string before or right after this call.

The aux string can contain any additional information whatever the input method engine want.

◆ show_lookup_table()

void scim::IMEngineInstanceBase::show_lookup_table ( )
protected

Show the lookup table area.

The lookup table should be updated by calling update_lookup_table before or right after this call.

◆ hide_preedit_string()

void scim::IMEngineInstanceBase::hide_preedit_string ( )
protected

Hide the preedit string area.

◆ hide_aux_string()

void scim::IMEngineInstanceBase::hide_aux_string ( )
protected

Hide the aux string area.

◆ hide_lookup_table()

void scim::IMEngineInstanceBase::hide_lookup_table ( )
protected

Hide the lookup table area.

◆ update_preedit_caret()

void scim::IMEngineInstanceBase::update_preedit_caret ( int caret)
protected

Update the preedit caret position in the preedit string.

Parameters
caret- the new position of the preedit caret.

◆ update_preedit_string()

void scim::IMEngineInstanceBase::update_preedit_string ( const WideString & str,
const AttributeList & attrs = AttributeList() )
protected

Update the content of the preedit string,.

Parameters
str- the string content
attrs- the string attributes

◆ update_aux_string()

void scim::IMEngineInstanceBase::update_aux_string ( const WideString & str,
const AttributeList & attrs = AttributeList() )
protected

Update the content of the aux string,.

Parameters
str- the string content
attrs- the string attribute

◆ update_lookup_table()

void scim::IMEngineInstanceBase::update_lookup_table ( const LookupTable & table)
protected

Update the content of the lookup table,.

FrontEnd may reduce the page size of the table according to screen resolution. If the page size is changed, FrontEnd will inform this engine instance by calling update_lookup_table_page_size method.

Parameters
table- the new LookupTable

◆ commit_string()

void scim::IMEngineInstanceBase::commit_string ( const WideString & str)
protected

Commit a string to the client application.

The preedit string should be hid before calling this method. Otherwise the clients which use OnTheSpot input mode will flicker annoyingly.

Parameters
str- the string to be committed.

◆ forward_key_event()

void scim::IMEngineInstanceBase::forward_key_event ( const KeyEvent & key)
protected

Forward a key event to the client application.

Parameters
key- the key event to be forwarded.

◆ register_properties()

void scim::IMEngineInstanceBase::register_properties ( const PropertyList & properties)
protected

Register all properties of this IMEngineInstance into the FrontEnd.

The old properties previously registered by other IMEngineInstance will be discarded, so for each time focus_in() is called, all properties should be registered no matter whether they had been registered before.

Parameters
propertiesthe PropertyList contains all of the properties.

◆ update_property()

void scim::IMEngineInstanceBase::update_property ( const Property & property)
protected

Update a registered property.

Update a property which already registered by register_properties () method.

Parameters
propertythe property to be updated.

◆ beep()

void scim::IMEngineInstanceBase::beep ( )
protected

Generate a short beep.

◆ start_helper()

void scim::IMEngineInstanceBase::start_helper ( const String & helper_uuid)
protected

Start a Client Helper process.

Parameters
helper_uuidThe UUID of the Helper object.

◆ stop_helper()

void scim::IMEngineInstanceBase::stop_helper ( const String & helper_uuid)
protected

Stop a Client Helper process which was started by start_helper.

Parameters
helper_uuidThe UUID of the Helper object.

◆ send_helper_event()

void scim::IMEngineInstanceBase::send_helper_event ( const String & helper_uuid,
const Transaction & trans )
protected

Send an events transaction to a client helper process.

Parameters
helper_uuidThe UUID of the Helper object.
transThe transaction which contains events.

◆ get_surrounding_text()

bool scim::IMEngineInstanceBase::get_surrounding_text ( WideString & text,
int & cursor,
int maxlen_before = -1,
int maxlen_after = -1 )
protected

Retrieves context around the insertion point.

Input methods typically want context in order to constrain input text based on existing text; this is important for languages such as Thai where only some sequences of characters are allowed.

Unlike other signal activation actions, this action will return the result immediately.

Parameters
textlocation to store the context string around the insertion point.
cursorlocation to store index of the insertion cursor within @text.
maxlen_beforethe maxmium length of context string to be retrieved before the cursor; -1 means unlimited.
maxlen_afterthe maxmium length of context string to be retrieved after the cursor; -1 means unlimited.
Returns
true if surrounding text was provided.

◆ delete_surrounding_text()

bool scim::IMEngineInstanceBase::delete_surrounding_text ( int offset,
int len )
protected

Ask the client to delete characters around the cursor position.

In order to use this function, you should first call get_surrounding_text () to get the current context, and call this function immediately afterwards to make sure that you know what you are deleting. You should also account for the fact that even if the signal was handled, the input context might not have deleted all the characters that were requested to be deleted.

Parameters
offsetoffset from cursor position in chars; a negative value means start before the cursor.
lennumber of characters to delete.
Returns
true if the signal was handled.

The documentation for this class was generated from the following file: