Thuban/Model/layer.py

# Copyright (c) 2001, 2002, 2003, 2004 by Intevation GmbH
# Authors:
# Bernhard Herzog <[email protected]>
# Jonathan Coles <[email protected]>
# Silke Reimer <[email protected]>
#
# This program is free software under the GPL (>=v2)
# Read the file COPYING coming with Thuban for details.

__version__ = "$Revision$"

import os
import warnings

from Thuban import _

from messages import LAYER_PROJECTION_CHANGED, LAYER_VISIBILITY_CHANGED, \
     LAYER_CHANGED, LAYER_SHAPESTORE_REPLACED, CLASS_CHANGED

import classification

from color import Transparent, Black
from base import TitledObject, Modifiable
from data import SHAPETYPE_POLYGON, SHAPETYPE_ARC, SHAPETYPE_POINT

import resource

from color import Color

shapetype_names = {SHAPETYPE_POINT: "Point",
                   SHAPETYPE_ARC: "Arc",
                   SHAPETYPE_POLYGON: "Polygon"}

class BaseLayer(TitledObject, Modifiable):

    """Base class for the layers."""

    def __init__(self, title, visible = True, projection = None):
        """Initialize the layer.

        title -- the title
        visible -- boolean. If true the layer is visible.
        """
        TitledObject.__init__(self, title)
        Modifiable.__init__(self)
        self.visible = visible
        self.projection = projection

    def Visible(self):
        """Return true if layer is visible"""
        return self.visible

    def SetVisible(self, visible):
        """Set the layer's visibility."""
        self.visible = visible
        self.issue(LAYER_VISIBILITY_CHANGED, self)

    def HasClassification(self):
        """Determine if this layer supports classifications."""
        return False

    def HasShapes(self):
        """Determine if this layer supports shapes."""
        return False

    def GetProjection(self):
        """Return the layer's projection."""
        return self.projection

    def SetProjection(self, projection):
        """Set the layer's projection."""
        self.projection = projection
        self.changed(LAYER_PROJECTION_CHANGED, self)

    def Type(self):
        return "Unknown"

class Layer(BaseLayer):

    """Represent the information of one geodata file (currently a shapefile)

    All children of the layer have the same type.

    A layer has fill and stroke colors. Colors should be instances of
    Color. They can also be Transparent, indicating no fill or no stroke.

    The layer objects send the following events, all of which have the
    layer object as parameter:

        TITLE_CHANGED -- The title has changed.
        LAYER_PROJECTION_CHANGED -- the projection has changed.
    """

    def __init__(self, title, data, projection = None,
                 fill = Transparent, 
                 stroke = Black, 
                 lineWidth = 1, 
                 visible = True):
        """Initialize the layer.

        title -- the title
        data -- datastore object for the shape data shown by the layer
        projection -- the projection object. Its Inverse method is
               assumed to map the layer's coordinates to lat/long
               coordinates
        fill -- the fill color or Transparent if the shapes are 
                not filled
        stroke -- the stroke color or Transparent if the shapes 
                are not stroked
        visible -- boolean. If true the layer is visible.

        colors are expected to be instances of Color class
        """
        BaseLayer.__init__(self, title, 
                                 visible = visible,
                                 projection = projection)

        self.__classification = None
        self.store = None

        self.SetShapeStore(data)

        self.classification_column = None
        self.SetClassificationColumn(None)
        self.SetClassification(None)

        self.__classification.SetDefaultLineColor(stroke)
        self.__classification.SetDefaultLineWidth(lineWidth)
        self.__classification.SetDefaultFill(fill)

        self.UnsetModified()

    def SetShapeStore(self, store):
        # Set the classification to None if there is a classification
        # and the new shapestore doesn't have a table with a suitable
        # column, i.e one with the same name and type as before
        # FIXME: Maybe we should keep it the same if the type is
        # compatible enough such as FIELDTYPE_DOUBLE and FIELDTYPE_INT
        if self.__classification is not None:
            columnname = self.classification_column
            columntype = self.GetFieldType(columnname)
            table = store.Table()
            if (columnname is not None
                and (not table.HasColumn(columnname)
                     or table.Column(columnname).type != columntype)):
                self.SetClassification(None)

        self.store = store

        self.changed(LAYER_SHAPESTORE_REPLACED, self)

    def ShapeStore(self):
        return self.store

    def Destroy(self):
        BaseLayer.Destroy(self)
        if self.__classification is not None:
            self.__classification.Unsubscribe(CLASS_CHANGED,
                                              self._classification_changed)

    def BoundingBox(self):
        """Return the layer's bounding box in the intrinsic coordinate system.

        If the layer has no shapes, return None.
        """
        return self.store.BoundingBox()

    def LatLongBoundingBox(self):
        """Return the layer's bounding box in lat/long coordinates.

        Return None, if the layer doesn't contain any shapes.
        """
        bbox = self.BoundingBox()
        if bbox is not None and self.projection is not None:
            bbox = self.projection.InverseBBox(bbox)
        return bbox

    def Type(self):
        return self.ShapeType();

    def ShapesBoundingBox(self, shapes):
        """Return a bounding box in lat/long coordinates for the given
        list of shape ids.

        If shapes is None or empty, return None.
        """

        if shapes is None or len(shapes) == 0: return None

        xs = []
        ys = []

        for id in shapes:
            bbox = self.Shape(id).compute_bbox()
            if self.projection is not None:
                bbox = self.projection.InverseBBox(bbox)
            left, bottom, right, top = bbox
            xs.append(left); xs.append(right)
            ys.append(bottom); ys.append(top)

        return (min(xs), min(ys), max(xs), max(ys))


    def GetFieldType(self, fieldName):
        if self.store:
            table = self.store.Table()
            if table.HasColumn(fieldName):
                return table.Column(fieldName).type
        return None

    def HasShapes(self):
        return True

    def NumShapes(self):
        """Return the number of shapes in the layer"""
        return self.store.NumShapes()

    def ShapeType(self):
        """Return the type of the shapes in the layer.

        The return value is one of the SHAPETYPE_* constants defined in
        Thuban.Model.data.
        """
        return self.store.ShapeType()

    def Shape(self, index):
        """Return the shape with index index"""
        return self.store.Shape(index)

    def ShapesInRegion(self, bbox):
        """Return an iterable over the shapes that overlap the bounding box.

        The bbox parameter should be the bounding box as a tuple in the
        form (minx, miny, maxx, maxy) in unprojected coordinates.
        """
        if self.projection is not None:
            # Ensure that region lies within the layer's bounding box
            # Otherwise projection of the region would lead to incorrect
            # values.
            clipbbox = self.ClipBoundingBox(bbox)
            bbox = self.projection.ForwardBBox(clipbbox)
        return self.store.ShapesInRegion(bbox)

    def GetClassificationColumn(self):
        return self.classification_column

    def SetClassificationColumn(self, column):
        """Set the column to classifiy on, or None. If column is not None
        and the column does not exist in the table, raise a ValueError.
        """
        if column:
            columnType = self.GetFieldType(column)
            if columnType is None:
                raise ValueError()
        changed = self.classification_column != column
        self.classification_column = column
        if changed:
            self.changed(LAYER_CHANGED, self)

    def HasClassification(self):
        return True

    def GetClassification(self):
        return self.__classification

    def SetClassification(self, clazz):
        """Set the classification used by this layer to 'clazz'

        If 'clazz' is None a default classification is created.

        This issues a LAYER_CHANGED event.
        """

        if self.__classification is not None:
            self.__classification.Unsubscribe(CLASS_CHANGED,
                                              self._classification_changed)

        if clazz is None:
            clazz = classification.Classification()

        self.__classification = clazz
        self.__classification.Subscribe(CLASS_CHANGED,
                                        self._classification_changed)

        self._classification_changed()

    def _classification_changed(self):
        """Called from the classification object when it has changed."""
        self.changed(LAYER_CHANGED, self)
 
    def TreeInfo(self):
        items = []

        items.append(_("Filename: %s") % self.ShapeStore().FileName())

        if self.Visible():
            items.append(_("Shown"))
        else:
            items.append(_("Hidden"))
        items.append(_("Shapes: %d") % self.NumShapes())

        bbox = self.LatLongBoundingBox()
        if bbox is not None:
            items.append(_("Extent (lat-lon): (%g, %g, %g, %g)") % tuple(bbox))
        else:
            items.append(_("Extent (lat-lon):"))
        items.append(_("Shapetype: %s") % shapetype_names[self.ShapeType()])

        if self.projection and len(self.projection.params) > 0:
            items.append((_("Projection"),
                        [str(param) for param in self.projection.params]))

        items.append(self.__classification)

        return (_("Layer '%s'") % self.Title(), items)

    def ClipBoundingBox(self, bbox):
        """ Clip bbox to layer's bounding box.

        Returns that part of bbox that lies within the layers bounding box.
        If bbox is completely outside of the layers bounding box, bbox is
        returned.  It is assumed that bbox has sensible values, i.e. bminx
        < bmaxx and bminy < bmaxy.
        """
        bminx, bminy, bmaxx, bmaxy = bbox
        lminx, lminy, lmaxx, lmaxy = self.LatLongBoundingBox()
        if bminx > lmaxx or bmaxx < lminx:
            left, right = bminx, bmaxx
        else:
            left = max(lminx, bminx)
            right = min(lmaxx, bmaxx)
        if bminy > lmaxy or bmaxy < lminy:
            bottom, top = bminy, bmaxy
        else:
            bottom = max(lminy, bminy)
            top = min(lmaxy, bmaxy)
        
        return (left, bottom, right, top)


if resource.has_gdal_support():
    import gdal
    from gdalconst import GA_ReadOnly

class RasterLayer(BaseLayer):

    MASK_NONE  = 0
    MASK_BIT   = 1
    MASK_ALPHA = 2

    def __init__(self, title, filename, projection = None, visible = True):
        """Initialize the Raster Layer.

        title -- title for the layer.

        filename -- file name of the source image.

        projection -- Projection object describing the projection which
                      the source image is in.

        visible -- True is the layer should initially be visible.

        Throws IOError if the filename is invalid or points to a file that
        is not in a format GDAL can use.
        """

        BaseLayer.__init__(self, title, visible = visible)

        self.projection = projection
        self.filename = os.path.abspath(filename)

        self.bbox = -1

        self.mask_type = self.MASK_BIT
        self.alpha_opacity = 1

        self.image_info = None

        if resource.has_gdal_support():
            #
            # temporarily open the file so that GDAL can test if it's valid.
            #
            dataset = gdal.Open(self.filename, GA_ReadOnly)

            if dataset is None:
                raise IOError()

            #
            # while we have the file, extract some basic information 
            # that we can display later
            #
            self.image_info = {}

            self.image_info["nBands"] = dataset.RasterCount
            self.image_info["Size"] = (dataset.RasterXSize, dataset.RasterYSize)
            self.image_info["Driver"] = dataset.GetDriver().ShortName

            # store some information about the individual bands
            # [min_value, max_value]
            a = self.image_info["BandData"] = []

            for i in range(1, dataset.RasterCount+1):
                band = dataset.GetRasterBand(i)
                a.append(band.ComputeRasterMinMax())

        self.UnsetModified()

    def BoundingBox(self):
        """Return the layer's bounding box in the intrinsic coordinate system.

        If the there is no support for images, or the file cannot
        be read, or there is no geographics information available, return None.
        """
        if not resource.has_gdal_support():
            return None

        if self.bbox == -1:
            dataset = gdal.Open(self.filename, GA_ReadOnly)
            if dataset is None:
                self.bbox = None
            else:
                geotransform = dataset.GetGeoTransform()
                if geotransform is None:
                    return None

                x = 0
                y = dataset.RasterYSize
                left = geotransform[0] +        \
                       geotransform[1] * x +    \
                       geotransform[2] * y

                bottom = geotransform[3] +      \
                         geotransform[4] * x +  \
                         geotransform[5] * y

                x = dataset.RasterXSize
                y = 0
                right = geotransform[0] +       \
                        geotransform[1] * x +   \
                        geotransform[2] * y

                top = geotransform[3] +         \
                      geotransform[4] * x +     \
                      geotransform[5] * y

                self.bbox = (left, bottom, right, top)

        return self.bbox

    def LatLongBoundingBox(self):
        bbox = self.BoundingBox()
        if bbox is None:
            return None

        if self.projection is not None:
            bbox = self.projection.InverseBBox(bbox)

        return bbox

    def Type(self):
        return "Image"

    def GetImageFilename(self):
        return self.filename

    def MaskType(self):
        """Return True if the mask should be used when rendering the layer."""
        return self.mask_type

    def SetMaskType(self, type):
        """Set the type of mask to use.

        type can be one of MASK_NONE, MASK_BIT, MASK_ALPHA

        If the state changes, a LAYER_CHANGED message is sent.
        """
        if type not in (self.MASK_NONE, self.MASK_BIT, self.MASK_ALPHA):
            raise ValueError("type is invalid")

        if type != self.mask_type: 
            self.mask_type = type
            self.changed(LAYER_CHANGED, self)

    def AlphaOpacity(self):
        """Return the level of opacity used in alpha blending, or None
        if mask type is not MASK_ALPHA.
        """
        if self.mask_type == self.MASK_ALPHA:
            return self.alpha_opacity
        else:
            return None

    def SetAlphaOpacity(self, op):
        """Set the level of alpha opacity. 

        0 <= op <= 1.

        The layer is fully opaque when op = 1.
        """
        if not (0 <= op <= 1):
            raise ValueError("op out of range")

        self.alpha_opacity = op

    def ImageInfo(self):
        return self.image_info

    def TreeInfo(self):
        items = []

        items.append(_("Filename: %s") % self.GetImageFilename())

        if self.Visible():
            items.append(_("Shown"))
        else:
            items.append(_("Hidden"))

        bbox = self.LatLongBoundingBox()
        if bbox is not None:
            items.append(_("Extent (lat-lon): (%g, %g, %g, %g)") % bbox)
        else:
            items.append(_("Extent (lat-lon):"))

        if self.projection and len(self.projection.params) > 0:
            items.append((_("Projection"),
                        [str(param) for param in self.projection.params]))

        return (_("Layer '%s'") % self.Title(), items)

1	bh	2228	# Copyright (c) 2001, 2002, 2003, 2004 by Intevation GmbH
2	bh	6	# Authors:
3			# Bernhard Herzog <[email protected]>
4	jonathan	412	# Jonathan Coles <[email protected]>
5	silke	2339	# Silke Reimer <[email protected]>
6	bh	6	#
7			# This program is free software under the GPL (>=v2)
8			# Read the file COPYING coming with Thuban for details.
9
10			__version__ = "$Revision$"
11
12	bh	1599	import os
13	bh	1219	import warnings
14	bh	171
15	jan	374	from Thuban import _
16	bh	6
17	bh	701	from messages import LAYER_PROJECTION_CHANGED, LAYER_VISIBILITY_CHANGED, \
18	jonathan	1427	LAYER_CHANGED, LAYER_SHAPESTORE_REPLACED, CLASS_CHANGED
19	bh	6
20	jonathan	437	import classification
21	bh	6
22	jonathan	1338	from color import Transparent, Black
23	bh	6	from base import TitledObject, Modifiable
24	bh	1558	from data import SHAPETYPE_POLYGON, SHAPETYPE_ARC, SHAPETYPE_POINT
25	bh	6
26	jonathan	1158	import resource
27	bh	723
28	jonathan	2551	from color import Color
29	jonathan	1158
30	bh	6	shapetype_names = {SHAPETYPE_POINT: "Point",
31			SHAPETYPE_ARC: "Arc",
32			SHAPETYPE_POLYGON: "Polygon"}
33
34			class BaseLayer(TitledObject, Modifiable):
35
36			"""Base class for the layers."""
37
38	jonathan	929	def __init__(self, title, visible = True, projection = None):
39	bh	6	"""Initialize the layer.
40
41			title -- the title
42			visible -- boolean. If true the layer is visible.
43			"""
44			TitledObject.__init__(self, title)
45			Modifiable.__init__(self)
46			self.visible = visible
47	jonathan	929	self.projection = projection
48	bh	6
49			def Visible(self):
50			"""Return true if layer is visible"""
51			return self.visible
52
53			def SetVisible(self, visible):
54			"""Set the layer's visibility."""
55			self.visible = visible
56			self.issue(LAYER_VISIBILITY_CHANGED, self)
57	bh	276
58	jonathan	929	def HasClassification(self):
59	bernhard	2343	"""Determine if this layer supports classifications."""
60	jonathan	929	return False
61	bh	276
62	jonathan	1273	def HasShapes(self):
63			"""Determine if this layer supports shapes."""
64			return False
65
66	jonathan	929	def GetProjection(self):
67			"""Return the layer's projection."""
68			return self.projection
69
70			def SetProjection(self, projection):
71	bernhard	2343	"""Set the layer's projection."""
72	jonathan	929	self.projection = projection
73			self.changed(LAYER_PROJECTION_CHANGED, self)
74
75	jonathan	2551	def Type(self):
76			return "Unknown"
77
78	bh	6	class Layer(BaseLayer):
79
80			"""Represent the information of one geodata file (currently a shapefile)
81
82			All children of the layer have the same type.
83
84			A layer has fill and stroke colors. Colors should be instances of
85	jonathan	1338	Color. They can also be Transparent, indicating no fill or no stroke.
86	bh	6
87			The layer objects send the following events, all of which have the
88			layer object as parameter:
89
90			TITLE_CHANGED -- The title has changed.
91			LAYER_PROJECTION_CHANGED -- the projection has changed.
92			"""
93
94	bh	723	def __init__(self, title, data, projection = None,
95	jonathan	1338	fill = Transparent,
96			stroke = Black,
97	jonathan	464	lineWidth = 1,
98	jonathan	771	visible = True):
99	bh	6	"""Initialize the layer.
100
101			title -- the title
102	bh	723	data -- datastore object for the shape data shown by the layer
103	bh	6	projection -- the projection object. Its Inverse method is
104			assumed to map the layer's coordinates to lat/long
105			coordinates
106	jonathan	1338	fill -- the fill color or Transparent if the shapes are
107	jonathan	610	not filled
108	jonathan	1338	stroke -- the stroke color or Transparent if the shapes
109	jonathan	610	are not stroked
110	bh	6	visible -- boolean. If true the layer is visible.
111
112			colors are expected to be instances of Color class
113			"""
114	jonathan	929	BaseLayer.__init__(self, title,
115			visible = visible,
116			projection = projection)
117	bh	276
118	bh	723	self.__classification = None
119	jonathan	1427	self.store = None
120	jonathan	481
121	bh	723	self.SetShapeStore(data)
122	jonathan	492
123	bh	1452	self.classification_column = None
124			self.SetClassificationColumn(None)
125	jonathan	492	self.SetClassification(None)
126
127	jonathan	464	self.__classification.SetDefaultLineColor(stroke)
128			self.__classification.SetDefaultLineWidth(lineWidth)
129	jonathan	412	self.__classification.SetDefaultFill(fill)
130	jonathan	364
131	jonathan	389	self.UnsetModified()
132
133	bh	723	def SetShapeStore(self, store):
134	jonathan	1427	# Set the classification to None if there is a classification
135			# and the new shapestore doesn't have a table with a suitable
136			# column, i.e one with the same name and type as before
137			# FIXME: Maybe we should keep it the same if the type is
138			# compatible enough such as FIELDTYPE_DOUBLE and FIELDTYPE_INT
139			if self.__classification is not None:
140	bh	1452	columnname = self.classification_column
141			columntype = self.GetFieldType(columnname)
142	jonathan	1427	table = store.Table()
143	bh	1452	if (columnname is not None
144			and (not table.HasColumn(columnname)
145			or table.Column(columnname).type != columntype)):
146	jonathan	1427	self.SetClassification(None)
147
148	bh	723	self.store = store
149	bh	179
150	bh	1142	self.changed(LAYER_SHAPESTORE_REPLACED, self)
151	bh	723
152			def ShapeStore(self):
153			return self.store
154
155	bh	258	def Destroy(self):
156	bh	260	BaseLayer.Destroy(self)
157	jonathan	1427	if self.__classification is not None:
158	bh	1452	self.__classification.Unsubscribe(CLASS_CHANGED,
159			self._classification_changed)
160	bh	258
161	bh	6	def BoundingBox(self):
162	bh	179	"""Return the layer's bounding box in the intrinsic coordinate system.
163
164			If the layer has no shapes, return None.
165			"""
166	bh	1535	return self.store.BoundingBox()
167	bh	6
168			def LatLongBoundingBox(self):
169	bh	179	"""Return the layer's bounding box in lat/long coordinates.
170	bh	6
171	bh	179	Return None, if the layer doesn't contain any shapes.
172			"""
173			bbox = self.BoundingBox()
174	bh	1983	if bbox is not None and self.projection is not None:
175			bbox = self.projection.InverseBBox(bbox)
176			return bbox
177	bh	179
178	jonathan	2551	def Type(self):
179			return self.ShapeType();
180
181	jonathan	828	def ShapesBoundingBox(self, shapes):
182			"""Return a bounding box in lat/long coordinates for the given
183			list of shape ids.
184
185			If shapes is None or empty, return None.
186			"""
187
188			if shapes is None or len(shapes) == 0: return None
189
190	bh	1983	xs = []
191			ys = []
192	jonathan	828
193			for id in shapes:
194	bh	1983	bbox = self.Shape(id).compute_bbox()
195			if self.projection is not None:
196			bbox = self.projection.InverseBBox(bbox)
197			left, bottom, right, top = bbox
198			xs.append(left); xs.append(right)
199			ys.append(bottom); ys.append(top)
200	jonathan	828
201	bh	1983	return (min(xs), min(ys), max(xs), max(ys))
202	jonathan	828
203
204	jonathan	464	def GetFieldType(self, fieldName):
205	jonathan	1427	if self.store:
206			table = self.store.Table()
207			if table.HasColumn(fieldName):
208			return table.Column(fieldName).type
209	bh	839	return None
210	jonathan	464
211	jonathan	1273	def HasShapes(self):
212			return True
213
214	bh	6	def NumShapes(self):
215			"""Return the number of shapes in the layer"""
216	bh	1535	return self.store.NumShapes()
217	bh	6
218			def ShapeType(self):
219			"""Return the type of the shapes in the layer.
220	bh	1535
221			The return value is one of the SHAPETYPE_* constants defined in
222			Thuban.Model.data.
223	bh	6	"""
224	bh	1535	return self.store.ShapeType()
225	bh	6
226			def Shape(self, index):
227			"""Return the shape with index index"""
228	bh	1535	return self.store.Shape(index)
229	jonathan	364
230	bh	1587	def ShapesInRegion(self, bbox):
231	bh	1593	"""Return an iterable over the shapes that overlap the bounding box.
232	bh	143
233	bh	1593	The bbox parameter should be the bounding box as a tuple in the
234			form (minx, miny, maxx, maxy) in unprojected coordinates.
235	bh	143	"""
236	jonathan	794	if self.projection is not None:
237	silke	2339	# Ensure that region lies within the layer's bounding box
238			# Otherwise projection of the region would lead to incorrect
239			# values.
240			clipbbox = self.ClipBoundingBox(bbox)
241			bbox = self.projection.ForwardBBox(clipbbox)
242	bh	1587	return self.store.ShapesInRegion(bbox)
243	bh	143
244	bh	1452	def GetClassificationColumn(self):
245			return self.classification_column
246	jonathan	1427
247	bh	1452	def SetClassificationColumn(self, column):
248			"""Set the column to classifiy on, or None. If column is not None
249			and the column does not exist in the table, raise a ValueError.
250	jonathan	1427	"""
251	bh	1452	if column:
252			columnType = self.GetFieldType(column)
253			if columnType is None:
254	jonathan	1427	raise ValueError()
255	bh	1452	changed = self.classification_column != column
256			self.classification_column = column
257			if changed:
258			self.changed(LAYER_CHANGED, self)
259	jonathan	1427
260	jonathan	929	def HasClassification(self):
261			return True
262	jonathan	725
263	jonathan	412	def GetClassification(self):
264			return self.__classification
265
266			def SetClassification(self, clazz):
267	jonathan	1338	"""Set the classification used by this layer to 'clazz'
268	jonathan	481
269	jonathan	1338	If 'clazz' is None a default classification is created.
270
271	jonathan	1427	This issues a LAYER_CHANGED event.
272	jonathan	492	"""
273	jonathan	481
274	jonathan	1427	if self.__classification is not None:
275	bh	1452	self.__classification.Unsubscribe(CLASS_CHANGED,
276			self._classification_changed)
277	jonathan	529
278	jonathan	1338	if clazz is None:
279			clazz = classification.Classification()
280	jonathan	529
281	jonathan	1427	self.__classification = clazz
282	bh	1452	self.__classification.Subscribe(CLASS_CHANGED,
283			self._classification_changed)
284	jonathan	1338
285	bh	1452	self._classification_changed()
286	jonathan	492
287	bh	1452	def _classification_changed(self):
288	jonathan	492	"""Called from the classification object when it has changed."""
289	jonathan	558	self.changed(LAYER_CHANGED, self)
290	jonathan	492
291	bh	217	def TreeInfo(self):
292			items = []
293
294	jonathan	1338	items.append(_("Filename: %s") % self.ShapeStore().FileName())
295	jan	1012
296	bh	217	if self.Visible():
297	jan	374	items.append(_("Shown"))
298	bh	217	else:
299	jan	374	items.append(_("Hidden"))
300			items.append(_("Shapes: %d") % self.NumShapes())
301	bh	217
302			bbox = self.LatLongBoundingBox()
303			if bbox is not None:
304	bh	2228	items.append(_("Extent (lat-lon): (%g, %g, %g, %g)") % tuple(bbox))
305	bh	217	else:
306	jan	374	items.append(_("Extent (lat-lon):"))
307			items.append(_("Shapetype: %s") % shapetype_names[self.ShapeType()])
308	bh	217
309	jonathan	736	if self.projection and len(self.projection.params) > 0:
310			items.append((_("Projection"),
311			[str(param) for param in self.projection.params]))
312
313	jonathan	412	items.append(self.__classification)
314	bh	217
315	jan	374	return (_("Layer '%s'") % self.Title(), items)
316	jonathan	382
317	silke	2339	def ClipBoundingBox(self, bbox):
318			""" Clip bbox to layer's bounding box.
319	jonathan	736
320	silke	2339	Returns that part of bbox that lies within the layers bounding box.
321			If bbox is completely outside of the layers bounding box, bbox is
322			returned. It is assumed that bbox has sensible values, i.e. bminx
323			< bmaxx and bminy < bmaxy.
324			"""
325			bminx, bminy, bmaxx, bmaxy = bbox
326			lminx, lminy, lmaxx, lmaxy = self.LatLongBoundingBox()
327			if bminx > lmaxx or bmaxx < lminx:
328			left, right = bminx, bmaxx
329			else:
330			left = max(lminx, bminx)
331			right = min(lmaxx, bmaxx)
332			if bminy > lmaxy or bmaxy < lminy:
333			bottom, top = bminy, bmaxy
334			else:
335			bottom = max(lminy, bminy)
336			top = min(lmaxy, bmaxy)
337
338			return (left, bottom, right, top)
339
340
341	jonathan	1158	if resource.has_gdal_support():
342			import gdal
343			from gdalconst import GA_ReadOnly
344
345	jonathan	929	class RasterLayer(BaseLayer):
346
347	jonathan	2562	MASK_NONE = 0
348			MASK_BIT = 1
349			MASK_ALPHA = 2
350
351	jonathan	929	def __init__(self, title, filename, projection = None, visible = True):
352			"""Initialize the Raster Layer.
353
354			title -- title for the layer.
355
356			filename -- file name of the source image.
357
358			projection -- Projection object describing the projection which
359			the source image is in.
360
361			visible -- True is the layer should initially be visible.
362	jonathan	961
363			Throws IOError if the filename is invalid or points to a file that
364			is not in a format GDAL can use.
365	jonathan	929	"""
366
367			BaseLayer.__init__(self, title, visible = visible)
368
369			self.projection = projection
370	bh	1599	self.filename = os.path.abspath(filename)
371	jonathan	929
372			self.bbox = -1
373
374	jonathan	2562	self.mask_type = self.MASK_BIT
375			self.alpha_opacity = 1
376	jonathan	2551
377			self.image_info = None
378
379	jonathan	1158	if resource.has_gdal_support():
380			#
381			# temporarily open the file so that GDAL can test if it's valid.
382			#
383			dataset = gdal.Open(self.filename, GA_ReadOnly)
384	jonathan	961
385	jonathan	1158	if dataset is None:
386			raise IOError()
387	jonathan	961
388	jonathan	2551	#
389			# while we have the file, extract some basic information
390			# that we can display later
391			#
392			self.image_info = {}
393
394			self.image_info["nBands"] = dataset.RasterCount
395			self.image_info["Size"] = (dataset.RasterXSize, dataset.RasterYSize)
396			self.image_info["Driver"] = dataset.GetDriver().ShortName
397
398			# store some information about the individual bands
399			# [min_value, max_value]
400			a = self.image_info["BandData"] = []
401
402			for i in range(1, dataset.RasterCount+1):
403			band = dataset.GetRasterBand(i)
404			a.append(band.ComputeRasterMinMax())
405
406	jonathan	929	self.UnsetModified()
407
408			def BoundingBox(self):
409			"""Return the layer's bounding box in the intrinsic coordinate system.
410
411	jonathan	1338	If the there is no support for images, or the file cannot
412			be read, or there is no geographics information available, return None.
413	jonathan	929	"""
414	jonathan	1158	if not resource.has_gdal_support():
415			return None
416
417	jonathan	929	if self.bbox == -1:
418			dataset = gdal.Open(self.filename, GA_ReadOnly)
419			if dataset is None:
420			self.bbox = None
421			else:
422	jonathan	961	geotransform = dataset.GetGeoTransform()
423			if geotransform is None:
424			return None
425
426			x = 0
427			y = dataset.RasterYSize
428			left = geotransform[0] + \
429			geotransform[1] * x + \
430			geotransform[2] * y
431
432			bottom = geotransform[3] + \
433			geotransform[4] * x + \
434			geotransform[5] * y
435
436			x = dataset.RasterXSize
437			y = 0
438			right = geotransform[0] + \
439			geotransform[1] * x + \
440			geotransform[2] * y
441
442			top = geotransform[3] + \
443			geotransform[4] * x + \
444			geotransform[5] * y
445
446	jonathan	929	self.bbox = (left, bottom, right, top)
447
448			return self.bbox
449
450			def LatLongBoundingBox(self):
451			bbox = self.BoundingBox()
452	jonathan	961	if bbox is None:
453	jonathan	929	return None
454
455	jonathan	961	if self.projection is not None:
456	bh	1983	bbox = self.projection.InverseBBox(bbox)
457	jonathan	961
458	bh	1983	return bbox
459	jonathan	961
460	jonathan	2551	def Type(self):
461			return "Image"
462
463	jonathan	929	def GetImageFilename(self):
464			return self.filename
465
466	jonathan	2562	def MaskType(self):
467	jonathan	2551	"""Return True if the mask should be used when rendering the layer."""
468	jonathan	2562	return self.mask_type
469	jonathan	2551
470	jonathan	2562	def SetMaskType(self, type):
471			"""Set the type of mask to use.
472	jonathan	2551
473	jonathan	2562	type can be one of MASK_NONE, MASK_BIT, MASK_ALPHA
474
475	jonathan	2551	If the state changes, a LAYER_CHANGED message is sent.
476			"""
477	jonathan	2562	if type not in (self.MASK_NONE, self.MASK_BIT, self.MASK_ALPHA):
478			raise ValueError("type is invalid")
479
480			if type != self.mask_type:
481			self.mask_type = type
482	jonathan	2551	self.changed(LAYER_CHANGED, self)
483
484	jonathan	2562	def AlphaOpacity(self):
485			"""Return the level of opacity used in alpha blending, or None
486			if mask type is not MASK_ALPHA.
487			"""
488			if self.mask_type == self.MASK_ALPHA:
489			return self.alpha_opacity
490			else:
491			return None
492
493			def SetAlphaOpacity(self, op):
494			"""Set the level of alpha opacity.
495
496			0 <= op <= 1.
497
498			The layer is fully opaque when op = 1.
499			"""
500			if not (0 <= op <= 1):
501			raise ValueError("op out of range")
502
503			self.alpha_opacity = op
504
505	jonathan	2551	def ImageInfo(self):
506			return self.image_info
507
508	jonathan	929	def TreeInfo(self):
509			items = []
510
511	jonathan	1338	items.append(_("Filename: %s") % self.GetImageFilename())
512
513	jonathan	929	if self.Visible():
514			items.append(_("Shown"))
515			else:
516			items.append(_("Hidden"))
517
518			bbox = self.LatLongBoundingBox()
519			if bbox is not None:
520			items.append(_("Extent (lat-lon): (%g, %g, %g, %g)") % bbox)
521			else:
522			items.append(_("Extent (lat-lon):"))
523
524			if self.projection and len(self.projection.params) > 0:
525			items.append((_("Projection"),
526			[str(param) for param in self.projection.params]))
527
528			return (_("Layer '%s'") % self.Title(), items)
529
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