## GwyLayerBasic

GwyLayerBasic — Display data colored with a gradient

## Synopsis

    #include <libgwydgets/gwydgets.h>

                        GwyLayerBasic;
                        GwyLayerBasicClass;
    GwyPixmapLayer*     gwy_layer_basic_new                 (void);
    void                gwy_layer_basic_get_range           (GwyLayerBasic *basic_layer,
                                                             gdouble *min,
                                                             gdouble *max);
    GwyLayerBasicRangeType gwy_layer_basic_get_range_type   (GwyLayerBasic *basic_layer);
    void                gwy_layer_basic_set_gradient_key    (GwyLayerBasic *basic_layer,
                                                             const gchar *key);
    const gchar*        gwy_layer_basic_get_gradient_key    (GwyLayerBasic *basic_layer);
    void                gwy_layer_basic_set_presentation_key
                                                            (GwyLayerBasic *basic_layer,
                                                             const gchar *key);
    const gchar*        gwy_layer_basic_get_presentation_key
                                                            (GwyLayerBasic *basic_layer);
    gboolean            gwy_layer_basic_get_has_presentation
                                                            (GwyLayerBasic *basic_layer);
    void                gwy_layer_basic_set_min_max_key     (GwyLayerBasic *basic_layer,
                                                             const gchar *prefix);
    const gchar*        gwy_layer_basic_get_min_max_key     (GwyLayerBasic *basic_layer);
    void                gwy_layer_basic_set_range_type_key  (GwyLayerBasic *basic_layer,
                                                             const gchar *key);
    const gchar*        gwy_layer_basic_get_range_type_key  (GwyLayerBasic *basic_layer);

## Object Hierarchy

      GObject
       +----GInitiallyUnowned
             +----GtkObject
                   +----GwyDataViewLayer
                         +----GwyPixmapLayer
                               +----GwyLayerBasic

## Properties

      "default-range-type"       GwyLayerBasicRangeType  : Read / Write
      "gradient-key"             gchar*                : Read / Write
      "min-max-key"              gchar*                : Read / Write
      "presentation-key"         gchar*                : Read / Write
      "range-type-key"           gchar*                : Read / Write

## Signals

      "presentation-switched"                          : Run First

## Description

GwyLayerBasic is a data view layer that can paint data with a false color gradient. It is not normally usable outside a GwyDataView.

The layer takes all infromation from its parent GwyDataView, therefore you do not set its properties directly, but you change them in the corresponding GwyContainer and/or use methods like `gwy_layer_basic_set_gradient_key()` to make the layer read a different value from the container.

Several types of mapping of data to colors are available, see GwyLayerBasicRangeType for their description.

## Details

### GwyLayerBasic

    typedef struct _GwyLayerBasic GwyLayerBasic;

### GwyLayerBasicClass

    typedef struct {
        GwyPixmapLayerClass parent_class;

        /* signals */
        void (*presentation_switched)(GwyLayerBasic *basic_layer);

        void (*reserved1)(void);
        void (*reserved2)(void);
    } GwyLayerBasicClass;

### gwy_layer_basic_new ()

    GwyPixmapLayer*     gwy_layer_basic_new                 (void);

Creates a new basic data displaying layer.

Returns : | The newly created layer.

### gwy_layer_basic_get_range ()

    void                gwy_layer_basic_get_range           (GwyLayerBasic *basic_layer,
                                                             gdouble *min,
                                                             gdouble *max);

Gets the range colors are mapped from in current mode.

This function does not take presentations into account. It always returns ther range corresponding to the underlying data even if a presentation is shown instead.

`basic_layer` : | A basic data view layer.
`min` : | Location to store range minimum to.
`max` : | Location to store range maximum to.

### gwy_layer_basic_get_range_type ()

    GwyLayerBasicRangeType gwy_layer_basic_get_range_type   (GwyLayerBasic *basic_layer);

Gets the current color mapping mode.

`basic_layer` : | A basic data view layer.
Returns : | The current color mapping mode.

Since 2.7

### gwy_layer_basic_set_gradient_key ()

    void                gwy_layer_basic_set_gradient_key    (GwyLayerBasic *basic_layer,
                                                             const gchar *key);

Sets the container key of the colour gradient to use to visualize data.

`basic_layer` : | A basic data view layer.
`key` : | Container string key identifying the color gradient to use.

### gwy_layer_basic_get_gradient_key ()

    const gchar*        gwy_layer_basic_get_gradient_key    (GwyLayerBasic *basic_layer);

Gets key identifying color gradient.

`basic_layer` : | A basic data view layer.
Returns : | The string key, or `NULL` if it isn't set.

### gwy_layer_basic_set_presentation_key ()

    void                gwy_layer_basic_set_presentation_key
                                                            (GwyLayerBasic *basic_layer,
                                                             const gchar *key);

Sets the container key of the data field to actually display by a basic layer.

The data field set with `gwy_pixmap_layer_get_data_key()` is used to obtain values, it determines physical dimensions, etc. When a data field is set with this method, it is displayed instead of the actual data.

`basic_layer` : | A basic data view layer.
`key` : | Container string key identifying the data field to actually display.

### gwy_layer_basic_get_presentation_key ()

    const gchar*        gwy_layer_basic_get_presentation_key
                                                            (GwyLayerBasic *basic_layer);

Gets the key identifying data field this pixmap layer actually displays.

See `gwy_layer_basic_set_presentation_key()` for details.

`basic_layer` : | A basic data view layer.
Returns : | The string key, or `NULL` if it isn't set.

### gwy_layer_basic_get_has_presentation ()

    gboolean            gwy_layer_basic_get_has_presentation
                                                            (GwyLayerBasic *basic_layer);

Tests whether a basic layer displays a presentation instead of the data.

`basic_layer` : | A basic data view layer.
Returns : | `TRUE` if the layer has a presentation, `FALSE` it it displays the data.

### gwy_layer_basic_set_min_max_key ()

    void                gwy_layer_basic_set_min_max_key     (GwyLayerBasic *basic_layer,
                                                             const gchar *prefix);

Sets basic layer fixed range minimum and maximum.

`basic_layer` : | A basic data view layer.
`prefix` : | Prefix of keys identifying minimum and maximum values for fixed range, "/min" and "/max" is appended to it to get the individual minimum and maximum keys.

### gwy_layer_basic_get_min_max_key ()

    const gchar*        gwy_layer_basic_get_min_max_key     (GwyLayerBasic *basic_layer);

Gets prefix identifying fixed range minimum and maximum.

`basic_layer` : | A basic data view layer.
Returns : | The prefix, or `NULL` if it isn't set.

### gwy_layer_basic_set_range_type_key ()

    void                gwy_layer_basic_set_range_type_key  (GwyLayerBasic *basic_layer,
                                                             const gchar *key);

Sets the container key of the color range mapping type to use to visualize data.

`basic_layer` : | A basic data view layer.
`key` : | Container string key identifying the range type to use.

### gwy_layer_basic_get_range_type_key ()

    const gchar*        gwy_layer_basic_get_range_type_key  (GwyLayerBasic *basic_layer);

Gets key identifying color range mapping type.

`basic_layer` : | A basic data view layer.
Returns : | The string key, or `NULL` if it isn't set.

## Property Details

### The `"default-range-type"` property

      "default-range-type"       GwyLayerBasicRangeType  : Read / Write

The :default-range-type-key property determines the color mapping range type used when the type is unset in the container.

Default value: GWY_LAYER_BASIC_RANGE_FULL

Since 2.7

### The `"gradient-key"` property

      "gradient-key"             gchar*                : Read / Write

The :gradient-key property is the container key used to identify GwyGradient data is colored with.

Default value: NULL

### The `"min-max-key"` property

      "min-max-key"              gchar*                : Read / Write

The :min-max-key property is the container key prefix used to identify fixed range minimum and maximum.

Default value: NULL

### The `"presentation-key"` property

      "presentation-key"         gchar*                : Read / Write

The :presentation-key property is the container key used to identify presentation data field .

Default value: NULL

### The `"range-type-key"` property

      "range-type-key"           gchar*                : Read / Write

The :range-type-key property is the container key used to identify color range type.

Default value: NULL

## Signal Details

### The `"presentation-switched"` signal

    void                user_function                      (GwyLayerBasic *gwydataview,
                                                            gpointer       user_data)        : Run First

The ::presentation-switched signal is emitted when the presentation state changes, that is when a layer which displayed data directly starts displaying a presentation, or conversely when it stops displaying a presentation.

`gwydataview` : | The GwyLayerBasic which received the signal.
`user_data` : | user data set when the signal handler was connected.

## See Also

GwyDataView -- data display widget, GwyLayerMask -- display data as color mask, GwyGradient -- color gradient representation