def __init__(self, image_file=None, default_wh=[1024.0, 1024.0], progress_handler = None):
self.clear()
self.image = None
if progress_handler:
self.ph = progress_handler
else:
self.ph = lambda i: None
self.ph._message = ''
self.ph._maxval = 0
if image_file and os.path.exists(image_file):
# image tracing shall consist of 256 index colors ranked by luma
img = QImage(image_file)
if not img.isGrayscale() and QMessageBox("Image is not in grayscale",
"Convert RGB image to grayscale?",
QMessageBox.Question,
QMessageBox.Yes, QMessageBox.No, 0).exec_() == QMessageBox.Yes:
self.ph._message = 'Converting image to grayscale'
self.ph._maxval = img.height()
for y in range(img.height()):
for x in range(img.width()):
lightness = qGray(img.pixel(x, y))
img.setPixel(x, y, (lightness<<16) + (lightness<<8) + lightness)
self.ph(y)
colortable = [QColor(i, i, i).rgb() for i in xrange(256)]
self.image = img.convertToFormat(QImage.Format_Indexed8, colortable)
w, h = float(self.image.width()), float(self.image.height())
self.dpi = img.dotsPerMeterX() / 1000.0 * 25.4
else:
w, h = default_wh
self.dpi = 96.0
self.wh = [w, h]
self.x1, self.y1, self.x2, self.y2 = [i/max(w, h) for i in [-w, -h, w, h]]
self.dx = self.x2 - self.x1
self.dy = self.y2 - self.y1
# Resolution field in SVG units per pixel
self.scale = self.dx / w
def getLegendGraphic(self, params):
qgsLayer = self.layerRegistry.mapLayer(params.get('layer'))
boxSpace = 1
layerSpace = 2
# layerTitleSpace = 3
symbolSpace = 2
iconLabelSpace = 2
symbolWidth = 5
symbolHeight = 3
drawLegendLabel = True
rootGroup = QgsLayerTreeGroup()
rootGroup.addLayer(qgsLayer)
# layer = QgsLayerTreeLayer(qgsLayer)
# if qgsLayer.title():
# layer.setLayerName(qgsLayer.title())
legendModel = QgsLayerTreeModel(rootGroup)
rootChildren = rootGroup.children()
img_tmp = QImage(QSize(1, 1), QImage.Format_ARGB32_Premultiplied)
dpm = 1 / 0.00028
img_tmp.setDotsPerMeterX(dpm)
img_tmp.setDotsPerMeterY(dpm)
dpmm = img_tmp.dotsPerMeterX() / 1000.0
del img_tmp
legendSettings = QgsLegendSettings()
legendSettings.setTitle('')
legendSettings.setBoxSpace(boxSpace)
legendSettings.rstyle(QgsComposerLegendStyle.Subgroup).setMargin(QgsComposerLegendStyle.Top, layerSpace)
legendSettings.rstyle(QgsComposerLegendStyle.Symbol).setMargin(QgsComposerLegendStyle.Top, symbolSpace)
legendSettings.rstyle(QgsComposerLegendStyle.SymbolLabel).setMargin(QgsComposerLegendStyle.Left, iconLabelSpace)
legendSettings.setSymbolSize(QSizeF(symbolWidth, symbolHeight))
# legendSettings.rstyle(QgsComposerLegendStyle.Subgroup).setFont(layerFont)
# legendSettings.rstyle(QgsComposerLegendStyle.SymbolLabel).setFont(itemFont)
# // TODO: not available: layer font color
# legendSettings.setFontColor( itemFontColor );
# for node in rootChildren:
# if (QgsLayerTree.isLayer(node)):
# QgsLegendRenderer.setNodeLegendStyle(node, QgsComposerLegendStyle.Subgroup)
# # rule item titles
# # if ( !mDrawLegendItemLabel )
# # for legendNode in legendModel.layerLegendNodes(nodeLayer):
# # legendNode.setUserLabel(' ')
# # }
legendRenderer = QgsLegendRenderer(legendModel, legendSettings)
minSize = legendRenderer.minimumSize()
s = QSize(minSize.width() * dpmm, minSize.height() * dpmm)
img = QImage(s, QImage.Format_ARGB32_Premultiplied)
# fill in the background
color = QColor(0, 0, 0, 0)
img.fill(color)
p = QPainter()
p.begin(img)
p.setRenderHint(QPainter.Antialiasing, True)
p.scale(dpmm, dpmm)
legendRenderer.drawLegend(p)
map_buffer = QBuffer()
map_buffer.open(QIODevice.ReadWrite)
img.save(map_buffer, 'PNG')
# clean up
map_buffer.close()
p.end()
# self.layerRegistry.removeAllMapLayers()
return map_buffer.data()
