Accessing and Modifying WISER State

Tool plugins and context-menu plugins can access and manipulate WISER application state through the ApplicationState class. The plugin can access an instance of this class via the "wiser" value in the context passed to the plugin.

class wiser.gui.app_state.ApplicationState(app, config: ApplicationConfig | None = None)

This class holds all WISER application state.

take_next_id() → int

Returns the next ID for use with an object, and also increments the internal “next ID” value.

get_loader()

Returns the RasterDataLoader instance being used by WISER to load data sets.

get_current_dir() → str

Returns the current directory of the application. This is the last directory that the user accessed in a load or save operation, so that the next load or save can start at the same directory.

set_current_dir(current_dir: str) → None

Sets the current directory of the application. This is the last directory that the user accessed in a load or save operation, so that the next load or save can start at the same directory.

update_cwd_from_path(path: str) → None

This helper function makes it easier to update the current working directory (CWD) at the end of a file-load or file-save operation. The specified path is assumed to be either a directory or a file:

• If it is a directory then the current directory is set to that path.

• If it is a file then the directory portion of the path is taken and used for the current directory.

The function only updates the current directory if the filesystem actually reports it as a valid directory. If the directory can’t be identified from the specified path (e.g. the OS doesn’t report the path as a valid directory), this function simply logs a warning.

open_file(file_path)

A general file-open operation in WISER. This method can be used for loading any kind of data file whose type and contents can be identified automatically. This operation should not be used for importing ASCII spectral data, regions of interest, etc. since WISER cannot identify the file’s contents automatically.

add_dataset(dataset: RasterDataSet, view_dataset: bool = True)

Add a dataset to the application state. A unique numeric ID is assigned to the dataset, which is also set on the dataset itself.

The method will fire a signal indicating that the dataset was added.

has_dataset(ds_id: int) → bool

Returns whether the dataset with the specified numeric ID is in the application state.

get_dataset(ds_id: int) → RasterDataSet

Return the dataset with the specified numeric ID. If the ID is unrecognized then a KeyError will be raised.

num_datasets()

Return the number of datasets in the application state.

get_datasets() → List[RasterDataSet]

Return a list of datasets in the application state. The returned list is separate from the internal application-state data structures, and therefore may be mutated by the caller without harm.

remove_dataset(ds_id: int)

Remove the dataset with the specified numeric ID from the application state and the cache. If the ID is unrecognized then a KeyError will be raised.

The method will fire a signal indicating that the dataset was removed.

multiple_datasets_same_size()

This function returns True if there are multiple datasets, and they are all the same size. If either of these cases is not true then False is returned.

multiple_displayed_datasets_same_size()

This function returns True if there are multiple visible datasets and they are all the same size.

add_spectral_library(library)

Add a spectral library to the application state, assigning a new ID to the library. The method will fire a signal indicating that the spectral library was added, including the ID assigned to the library.

has_spectral_library(lib_id: int) → bool

Returns whether the spectral library with the specified numeric ID is in the application state.

get_spectral_library(lib_id)

Return the spectral library with the specified ID. If the ID is unrecognized, a KeyError will be raised.

num_spectral_libraries()

Return the number of spectral libraries in the application state.

get_spectral_libraries()

Return a list of all the spectral libraries in the application state.

remove_spectral_library(lib_id)

Remove the specified spectral library from the application state. The method will fire a signal indicating that the spectral library was removed.

get_config(option: str, default=None, as_type=None)

Returns the value of the specified config option. An optional default value may be specified.

Options are specified as a sequence of names separated by dots ‘.’, just like a series of object-member accesses on an object hierarchy.

set_config(option, value)

Sets the value of the specified config option.

add_roi(roi: RegionOfInterest, make_name_unique=False) → None

Add a Region of Interest to WISER’s state. A ValueError is raised if the ROI does not have a unique name.

remove_roi(roi_id: int) → None

Removes the specified Region of Interest from WISER’s state. A KeyError is raised if no ROI has the specified ID.

get_roi(**kwargs) → RegionOfInterest | None

Retrieve a Region of Interest from WISER’s state. The caller may specify an id keyword-argument to retrieve an ROI by ID, or a name keyword-argument to retrieve an ROI by name. Names are case-sensitive.

get_rois() → List[RegionOfInterest]

Returns a list of all Regions of Interest in WISER’s application state.

has_spectrum(spectrum_id: int) → bool

Returns whether the spectrum with the specified numeric ID is in the application state.

get_spectrum(spectrum_id: int) → Spectrum

Retrieve a spectrum from WISER’s state. A KeyError is raised if the ID doesn’t correspond to a spectrum.

get_all_spectra()

Retrieves all spectra in the spectrum plot.

get_active_spectrum()

Retrieve the current active spectrum. The “active spectrum” is the spectrum that the user most recently selected, or it may be the output of a band-math expression, plugin, etc. that computes a spectrum.

set_active_spectrum(spectrum: Spectrum)

Set the current active spectrum to be the specified spectrum. The “active spectrum” is the spectrum that the user most recently selected, or it may be the output of a band-math expression, plugin, etc. that computes a spectrum.

collect_spectrum(spectrum: Spectrum)

Add the specified spectrum to the “collected spectra” group.

Note that the specified spectrum cannot be the current “active spectrum”; if it is, a RuntimeError will be raised. The current “active spectrum” is collected via the collect_active_spectrum() method.

collect_active_spectrum()

Add the current “active spectrum” to the “collected spectra” group.

A RuntimeError will be raised if there is no active spectrum when this method is called.

get_collected_spectra() → List[Spectrum]

Returns the current list of collected spectra.

remove_collected_spectrum(index)

Removes a collected spectrum from the list of collected spectra. The spectrum to remove is specified by a 0-based index.

remove_all_collected_spectra()

Removes all spectra from the list of collected spectra.

show_spectra_in_plot(spectra: List[Spectrum], plot_title: str | None = None)

Takes the list of spectra passed in and displays it in a generic spectrum plot.

show_table_widget(header: List[str], rows: List[List[Any]], window_title: str | None = None, description: str | None = None)

Creates and shows a table widget that is meant for display.

show_matplotlib_display_widget(figure: Figure, axes: Axes, window_title: str | None = None, description: str | None = None)

Creates and shows a widget with a matplotlib plot

Operations involving loading and storing raster data sets will require the use of a loader object, also accessible off of the ApplicationState object. See the get_loader() function above. The loader offers these operations:

class wiser.raster.RasterDataLoader

A loader for loading 2D raster data-sets from the local filesystem, using GDAL (Geospatial Data Abstraction Library) for reading the data.

load_normal_dataset(impl: RasterDataImpl, data_cache: DataCache) → List[RasterDataSet]

The normal way to load in a dataset

load_from_file(path, data_cache=None, interactive=True, subdataset_name='') → List[RasterDataSet]

Load a raster data-set from the specified path. Returns a list of RasterDataSet object.

dataset_from_numpy_array(arr: ndarray, cache: DataCache = None) → RasterDataSet

Given a NumPy ndarray, this function returns a RasterDataSet object that uses the array for its raster data. The input ndarray must have three dimensions; they are interpreted as [spectral][spatial_y][spatial_x].

Raises a ValueError if the input array doesn’t have 3 dimensions.

Loading Raster Data into WISER

The above classes expose two ways to load raster data into WISER. The first option is to use the ApplicationState.open_file() function, which simply loads a file into WISER. Several kinds of files (raster images, spectral libraries, and a few other kinds of files) are supported by this method. No value is returned, so this function is not useful for getting access to the contents of a specific raster file.

To open a raster data file and get back an object to access its contents requires the use of the RasterDataLoader. The loader is accessed from the ApplicationState.get_loader() method, as described above. Note that any raster image loaded this way is not automatically displayed; after it has been loaded and possibly manipulated, it must be added to the ApplicationState object with the add_dataset() method, before it will be displayed.

Similarly, a NumPy array can be converted into a RasterDataSet object using the RasterDataLoader.dataset_from_numpy_array() method. It will likely be desirable to add metadata to the resulting RasterDataSet object (it is convenient to copy it from an existing data-set, if the new object was generated from an existing data-set), but this is not required.

Finally, it is not advisable to change a RasterDataSet object after handing it to WISER for display, as WISER currently expects that the object will not change once it has been given to WISER.