- globalmapper.GetLayerInfo(GM_LayerHandle_t32 aLayer) GM_LayerInfo_t ¶
Retrieves information about the given layer. If the layer is not loaded, nothing is returned. Otherwise, information about the layer is returned as a GM_LayerInfo_t object.
The GM_LayerInfo_t object is a comprehensive container of all the stored useful data about a layer. If you want to fetch a specific piece of data, reference it as a variable of the info object. For example, this is one way to get a bounding box for an entire layer:
info = gm.GetLayerInfo(the_layer) bounding_box = info.mGlobalRect
aLayer (GM_LayerHandle_t32) – the layer to retrieve info for
The layer’s metadata, or 0
- Return type
Below is the complete list of values for a layer that can be grabbed from a GM_LayerInfo_t object. You can also call print(…) on the info object to see all the values displayed at once. Note that the variables labeled RASTER/ELEV/VECTOR ONLY will still be present regardless of layer type; they may just have default values if the layer is not of the corresponding type.
mArchiveFilename: - Filename within archive file (e.g. .zip or .tar.gz) from which layer was loaded, if any (might be NULL)
mBandBitDepth: - RASTER/ELEV ONLY: number of bits per band value. Multiply by mNumBands to get total bit depth per sample.
mBandValType: - RASTER/ELEV ONLY: type of data for the bands
mCodePage: - Code page for text in layer. 0 is default and current active code page (CP_ACP). CP_UTF8 is for UTF-8 interpretation.
mControlPoints: - RASTER ONLY: The array of Ground Control Points for the layer. It’s stored as a pointer to a GM_GroundControlPoint_t, so use GM_GroundControlPoint_array_frompointer(…) to convert into an indexable array.
mDescription: - Layer description string
mDfltViewGlobal: - Default view bounding rectangle of layer in global coordinates (usually same as mGlobalRect)
mElevUnits: - Elevation units for layer
mEnabled: - Is this layer enabled for display or it it hidden?
mExtraLoadFlags: - Additional load flags with options selected by user during load. Pass these to GM_LoadLayerListEx to remember options.
mFilename: - Filename from which layer was loaded. If this is an archive file, like .zip, then the name of the actual loaded file will be in mArchiveFilename
mGlobalPixelHeight: - RASTER/ELEV ONLY: Approximate number of pixels required in height for a 1:1 pixel mapping in the current projection
mGlobalPixelWidth: - RASTER/ELEV ONLY: Approximate number of pixels required in width for a 1:1 pixel mapping in the current projection
mGlobalRect: - Bounding rectangle of the layer in global coordinates
mGroupName: - Group name that the layer is in. Empty string if part of no group. Separated with <sep> if multiple levels.
mHasRasterData: - Does this layer have raster or elevation data?
mHasVectorData: - Does this layer have vector data?
mLayerFlags: - Extra GM_LayerFlags_t32 flags for the layer
mMaxElevation: - ELEV ONLY: Maximum elevation in meters
mMetadataList: - List of metadata attributes and values for the layer. Stored as a pointer to a GM_AttrValue_t, so use GM_AttrValue_array_frompointer(…) to convert into an indexable array.
mMetadataListSize: - Number of metadata attributes in mMetadataList
mMinElevation: - ELEV ONLY: Minimum elevation in meters
mNativeProj: - Native projection of layer
mNativeRect: - Bounding rectangle of layer in native coordinates
mNumAreas: - VECTOR ONLY: Number of area features
mNumBands: - Number of bands in a raster image (use SetRasterDisplayOptions to change color band layout)
mNumGCPs: - Number of ground control points in mControlPoints
mNumLidarPoints: - VECTOR ONLY: Number of Lidar point cloud points (fetch individual points with GetLidarPoint)
mNumLines: - VECTOR ONLY: Number of line features
mNumPoints: - VECTOR ONLY: Number of point features
mPalette: - Array of palette entries for palette-based raster layer. Stored as a pointer to a GM_PaletteEntry_t, so use GM_PaletteEntry_array_frompointer(…) to convert into an indexable array.
mPaletteSize: - Number of palette entries in mPalette
mParentLayer: - Handle to parent layer if this is a child (i.e. from catalog or online layer). Will be 0 for all top-level layers.
mPixelHeight: - RASTER/ELEV ONLY: Layer’s height in number of pixels
mPixelSizeX: - RASTER/ELEV ONLY: Size of one pixel, in meters, in the x direction
mPixelSizeY: - RASTER/ELEV ONLY: Size of one pixel, in meters, in the y direction
mPixelWidth: - RASTER/ELEV ONLY: Layer’s width in number of pixels
mRasterTypeFlags: - Raster type flags (GM_RasterTypeFlags_t32), specifies what type of data a raster layer actually contains
mTypeName: - Layer type name
mUsedDefaultPos: - RASTER/ELEV ONLY: Was the default position used for this layer since the file could not be automatically positioned?
mUsedDefaultProj: - Was the default projection used for this layer since a projection for the file could not be automatically determined?
mUserData: - Custom data associated with layer provided by user via SetLayerUserData function
mUserText: - Custom text string associated with layer provided by user via SetLayerUserText function or loaded form workspace