## InfAdoptedRequestLog InfAdoptedRequestLog — History of requests |

## Stability Level

Unstable, unless otherwise indicated

## Synopsis

    #include <libinfinity/adopted/inf-adopted-request-log.h>

                        InfAdoptedRequestLog;
    struct              InfAdoptedRequestLogClass;
    InfAdoptedRequestLog * inf_adopted_request_log_new      (guint user_id);
    guint               inf_adopted_request_log_get_user_id (InfAdoptedRequestLog *log);
    guint               inf_adopted_request_log_get_begin   (InfAdoptedRequestLog *log);
    guint               inf_adopted_request_log_get_end     (InfAdoptedRequestLog *log);
    gboolean            inf_adopted_request_log_is_empty    (InfAdoptedRequestLog *log);
    void                inf_adopted_request_log_set_begin   (InfAdoptedRequestLog *log,
                                                             guint n);
    InfAdoptedRequest * inf_adopted_request_log_get_request (InfAdoptedRequestLog *log,
                                                             guint n);
    void                inf_adopted_request_log_add_request (InfAdoptedRequestLog *log,
                                                             InfAdoptedRequest *request);
    void                inf_adopted_request_log_remove_requests
                                                            (InfAdoptedRequestLog *log,
                                                             guint up_to);
    InfAdoptedRequest * inf_adopted_request_log_next_associated
                                                            (InfAdoptedRequestLog *log,
                                                             InfAdoptedRequest *request);
    InfAdoptedRequest * inf_adopted_request_log_prev_associated
                                                            (InfAdoptedRequestLog *log,
                                                             InfAdoptedRequest *request);
    InfAdoptedRequest * inf_adopted_request_log_original_request
                                                            (InfAdoptedRequestLog *log,
                                                             InfAdoptedRequest *request);
    InfAdoptedRequest * inf_adopted_request_log_next_undo   (InfAdoptedRequestLog *log);
    InfAdoptedRequest * inf_adopted_request_log_next_redo   (InfAdoptedRequestLog *log);
    InfAdoptedRequest * inf_adopted_request_log_upper_related
                                                            (InfAdoptedRequestLog *log,
                                                             guint n);
    InfAdoptedRequest * inf_adopted_request_log_lower_related
                                                            (InfAdoptedRequestLog *log,
                                                             guint n);

## Object Hierarchy

      GObject
       +----InfAdoptedRequestLog

## Properties

      "begin"                    guint                 : Read / Write / Construct Only
      "end"                      guint                 : Read
      "next-redo"                InfAdoptedRequest*    : Read
      "next-undo"                InfAdoptedRequest*    : Read
      "user-id"                  guint                 : Read / Write / Construct Only

## Signals

      "add-request"                                    : Run Last

## Description

InfAdoptedRequestLog stores all requests by a particular user. These need to be looked up by InfAdoptedAlgorithm to perform transformations of older requests to the current state. It also adds relations between the requests so that is easy to find the request that an Undo request undoes, or the Undo request undoing a given request, if available.

When requests are no longer needed, then they can also be removed again from the log, however requests can only be removed so that remaining Undo or Redo requests do not refer to some request that is about to be removed.

## Details

### InfAdoptedRequestLog

    typedef struct _InfAdoptedRequestLog InfAdoptedRequestLog;

InfAdoptedRequestLog is an opaque data type. You should only access it via the public API functions.

### struct InfAdoptedRequestLogClass

    struct InfAdoptedRequestLogClass {
      void(*add_request)(InfAdoptedRequestLog* request_log,
                         InfAdoptedRequest* request);
    };

This structure contains the default signal handlers for InfAdoptedRequestLog.

`add_request` () | Default signal handler for the "add-request" signal.

### inf_adopted_request_log_new ()

    InfAdoptedRequestLog * inf_adopted_request_log_new      (guint user_id);

`user_id` : | The ID of the InfAdoptedUser to create a request log for. The request log only contains requests of that particular user.
Returns : | A new InfAdoptedRequestLog.

### inf_adopted_request_log_get_user_id ()

    guint               inf_adopted_request_log_get_user_id (InfAdoptedRequestLog *log);

Returns the ID of the user whose requests `log` contains.

`log` : | A InfAdoptedRequestLog.
Returns : | The log's user ID.

### inf_adopted_request_log_get_begin ()

    guint               inf_adopted_request_log_get_begin   (InfAdoptedRequestLog *log);

Returns the first index (i.e. the index of the oldest request) in the log.

`log` : | A InfAdoptedRequestLog.
Returns : | The first index in the log.

### inf_adopted_request_log_get_end ()

    guint               inf_adopted_request_log_get_end     (InfAdoptedRequestLog *log);

Returns the index a newly inserted request would have (i.e. one past the index of the newest request in the log). This ensures that `inf_adopted_request_log_get_end()` - `inf_adopted_request_log_get_begin()` reveals the number of requests in the log.

`log` : | A InfAdoptedRequestLog.
Returns : | The index of the next request in the log.

### inf_adopted_request_log_is_empty ()

    gboolean            inf_adopted_request_log_is_empty    (InfAdoptedRequestLog *log);

Returns whether `log` is empty. A log is empty if it does not contain any requsets.

`log` : | A InfAdoptedRequestLog.
Returns : | Whether `log` is empty.

### inf_adopted_request_log_set_begin ()

    void                inf_adopted_request_log_set_begin   (InfAdoptedRequestLog *log,
                                                             guint n);

This function sets the index of the first log that will be added to `log`. For a new request log, this is set to 0. If you intend to insert a request sequence into `log` that does not start with 0, then you can call this function with the desired start index, so that `inf_adopted_request_log_get_begin()` and `inf_adopted_request_log_get_end()` return the correct value.

If you don't need `inf_adopted_request_log_get_begin()` or `inf_adopted_request_log_get_end()` before adding the first request to the log, then you don't need to call this function, since `inf_adopted_request_log_add_request()` will do it implicitely based on the request's vector time component for the request log's user.

This function can only be called if the request log is empty, see `inf_adopted_request_log_is_empty()`.

`log` : | A InfAdoptedRequestLog.
`n` : | The index of the first request to be added to the log.

### inf_adopted_request_log_get_request ()

    InfAdoptedRequest * inf_adopted_request_log_get_request (InfAdoptedRequestLog *log,
                                                             guint n);

Returns the request with the given index. Such a request must exist in `log`.

`log` : | A InfAdoptedRequestLog.
`n` : | The index of a request contained in `log`.
Returns : | A InfAdoptedRequest. The request is owned by the request log, you do not need to free it.

### inf_adopted_request_log_add_request ()

    void                inf_adopted_request_log_add_request (InfAdoptedRequestLog *log,
                                                             InfAdoptedRequest *request);

### inf_adopted_request_log_remove_requests ()

    void                inf_adopted_request_log_remove_requests
                                                            (InfAdoptedRequestLog *log,
                                                             guint up_to);

Removes all requests with index lower than `up_to`. This function only works if the request before `up_to` is an "upper related" request. See `inf_adopted_request_log_upper_related()`. This condition guarantees that remaining requests do not refer to removed ones.

`log` : | A InfAdoptedRequestLog.
`up_to` : | The index of the first request not to remove.

### inf_adopted_request_log_next_associated ()

    InfAdoptedRequest * inf_adopted_request_log_next_associated
                                                            (InfAdoptedRequestLog *log,
                                                             InfAdoptedRequest *request);

If `request` is of type `INF_ADOPTED_REQUEST_DO` or `INF_ADOPTED_REQUEST_REDO`, this returns UNDO request that undoes this request, if any. If `request` is a `INF_ADOPTED_REQUEST` UNDO request, this returns a request that redoes `request`, if any.

`log` : | A InfAdoptedRequestLog.
`request` : | A InfAdoptedRequest contained in `log`.
Returns : | The next associated request of `request`, or `NULL`.

### inf_adopted_request_log_prev_associated ()

    InfAdoptedRequest * inf_adopted_request_log_prev_associated
                                                            (InfAdoptedRequestLog *log,
                                                             InfAdoptedRequest *request);

If `request` is of type `INF_ADOPTED_REQUEST_REDO` or, this returns the UNDO request that is redone by `request`, if `request` is a `INF_ADOPTED_REQUEST_UNDO` request, this returns the request that is undone by `request`.

`request` must either be contained in `log` or the vector time component of its own user must be equivalent to `inf_adopted_request_log_get_end()`, in which case `request` is treated as it if was the newest requset in `log`.

`log` : | A InfAdoptedRequestLog.
`request` : | A InfAdoptedRequest.
Returns : | The previous associated request of `request`, or `NULL`.

### inf_adopted_request_log_original_request ()

    InfAdoptedRequest * inf_adopted_request_log_original_request
                                                            (InfAdoptedRequestLog *log,
                                                             InfAdoptedRequest *request);

Returns the most previous associated request for `request`, that is, the `INF_ADOPTED_REQUEST_DO` request that `request` undoes or redoes, respectively. If `request` itself is a `INF_ADOPTED_REQUEST_DO` request, `request` itself is returned.

`request` must either be contained in `log` or the vector time component of its own user must be equivalent to `inf_adopted_request_log_get_end()`, in which case `request` is treated as it if was the newest request in `log`.

`log` : | A InfAdoptedRequestLog.
`request` : | A InfAdoptedRequest.
Returns : | The original request of `request`. This function never returns `NULL`.

### inf_adopted_request_log_next_undo ()

    InfAdoptedRequest * inf_adopted_request_log_next_undo   (InfAdoptedRequestLog *log);

Returns the request that would be undone if a undo request was added to the request log.

`log` : | A InfAdoptedRequestLog.
Returns : | The next request to be undone, or `NULL`.

### inf_adopted_request_log_next_redo ()

    InfAdoptedRequest * inf_adopted_request_log_next_redo   (InfAdoptedRequestLog *log);

Returns the request that would be redone if a redo request was added to the request log.

`log` : | A InfAdoptedRequestLog.
Returns : | The next request to be redone, or `NULL`.

### inf_adopted_request_log_upper_related ()

    InfAdoptedRequest * inf_adopted_request_log_upper_related
                                                            (InfAdoptedRequestLog *log,
                                                             guint n);

Returns the newest request in `log` that is related to `n`th request in log. requests are considered related when they are enclosed by a do/undo, an undo/redo or a redo/undo pair.

Note that the sets of related requests within a request log are disjoint.

`log` : | A InfAdoptedRequestLog.
`n` : | Index of a request in `log`.
Returns : | The newest request in `log` being related to the `n`th request.

### inf_adopted_request_log_lower_related ()

    InfAdoptedRequest * inf_adopted_request_log_lower_related
                                                            (InfAdoptedRequestLog *log,
                                                             guint n);

Returns the oldest request in `log` that is related to `n`th request in log. Requests are considered related when they are enclosed by a do/undo, an undo/redo or a redo/undo pair.

Note that the sets of related requests within a request log are disjoint.

`log` : | A InfAdoptedRequestLog.
`n` : | Index of a request in `log`.
Returns : | The oldest request in `log` being related to the `n`th request.

## Property Details

### The `"begin"` property

      "begin"                    guint                 : Read / Write / Construct Only

The first index contained in the log.

Default value: 0

### The `"end"` property

      "end"                      guint                 : Read

The index of the next request that is inserted into the log.

Default value: 0

### The `"next-redo"` property

      "next-redo"                InfAdoptedRequest*    : Read

The request that is redone when the user issues a redo request new.

### The `"next-undo"` property

      "next-undo"                InfAdoptedRequest*    : Read

The request that is undone when the user issues an undo request now.

### The `"user-id"` property

      "user-id"                  guint                 : Read / Write / Construct Only

The ID of the user whose requests the log contains.

Default value: 0

## Signal Details

### The `"add-request"` signal

    void                user_function                      (InfAdoptedRequestLog *request_log,
                                                            InfAdoptedRequest    *request,
                                                            gpointer              user_data)        : Run Last

This signal is emitted whenever a new request is added to the request log via `inf_adopted_request_log_add_request()`.

`request_log` : | The InfAdoptedRequestLog to which a new request is added.
`request` : | The new request being added.
`user_data` : | user data set when the signal handler was connected.

## See Also

InfAdoptedRequest, InfAdoptedAlgorithm