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+# coding: utf-8
+# /*##########################################################################
+#
+# Copyright (c) 2016-2017 European Synchrotron Radiation Facility
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in
+# all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+# THE SOFTWARE.
+#
+# ###########################################################################*/
+"""Text rasterisation feature leveraging Qt font and text layout support."""
+
+__authors__ = ["T. Vincent"]
+__license__ = "MIT"
+__date__ = "13/10/2016"
+
+
+import logging
+import sys
+import numpy
+from .. import qt
+from .._utils import convertQImageToArray
+
+
+_logger = logging.getLogger(__name__)
+
+
+def getDefaultFontFamily():
+ """Returns the default font family of the application"""
+ return qt.QApplication.instance().font().family()
+
+
+# Font weights
+ULTRA_LIGHT = 0
+"""Lightest characters: Minimum font weight"""
+
+LIGHT = 25
+"""Light characters"""
+
+NORMAL = 50
+"""Normal characters"""
+
+SEMI_BOLD = 63
+"""Between normal and bold characters"""
+
+BOLD = 74
+"""Thicker characters"""
+
+BLACK = 87
+"""Really thick characters"""
+
+ULTRA_BLACK = 99
+"""Thickest characters: Maximum font weight"""
+
+
+def rasterText(text, font,
+ size=-1,
+ weight=-1,
+ italic=False,
+ devicePixelRatio=1.0):
+ """Raster text using Qt.
+
+ It supports multiple lines.
+
+ :param str text: The text to raster
+ :param font: Font name or QFont to use
+ :type font: str or :class:`QFont`
+ :param int size:
+ Font size in points
+ Used only if font is given as name.
+ :param int weight:
+ Font weight in [0, 99], see QFont.Weight.
+ Used only if font is given as name.
+ :param bool italic:
+ True for italic font (default: False).
+ Used only if font is given as name.
+ :param float devicePixelRatio:
+ The current ratio between device and device-independent pixel
+ (default: 1.0)
+ :return: Corresponding image in gray scale and baseline offset from top
+ :rtype: (HxW numpy.ndarray of uint8, int)
+ """
+ if not text:
+ _logger.info("Trying to raster empty text, replaced by white space")
+ text = ' ' # Replace empty text by white space to produce an image
+
+ if not isinstance(font, qt.QFont):
+ font = qt.QFont(font, size, weight, italic)
+
+ metrics = qt.QFontMetrics(font)
+ size = metrics.size(qt.Qt.TextExpandTabs, text)
+ bounds = metrics.boundingRect(
+ qt.QRect(0, 0, size.width(), size.height()),
+ qt.Qt.TextExpandTabs,
+ text)
+
+ if (devicePixelRatio != 1.0 and
+ not hasattr(qt.QImage, 'setDevicePixelRatio')): # Qt 4
+ _logger.error('devicePixelRatio not supported')
+ devicePixelRatio = 1.0
+
+ # Add extra border and handle devicePixelRatio
+ width = bounds.width() * devicePixelRatio + 2
+ # align line size to 32 bits to ease conversion to numpy array
+ width = 4 * ((width + 3) // 4)
+ image = qt.QImage(width,
+ bounds.height() * devicePixelRatio,
+ qt.QImage.Format_RGB888)
+ if (devicePixelRatio != 1.0 and
+ hasattr(image, 'setDevicePixelRatio')): # Qt 5
+ image.setDevicePixelRatio(devicePixelRatio)
+
+ # TODO if Qt5 use Format_Grayscale8 instead
+ image.fill(0)
+
+ # Raster text
+ painter = qt.QPainter()
+ painter.begin(image)
+ painter.setPen(qt.Qt.white)
+ painter.setFont(font)
+ painter.drawText(bounds, qt.Qt.TextExpandTabs, text)
+ painter.end()
+
+ array = convertQImageToArray(image)
+
+ # RGB to R
+ array = numpy.ascontiguousarray(array[:, :, 0])
+
+ # Remove leading and trailing empty columns but one on each side
+ column_cumsum = numpy.cumsum(numpy.sum(array, axis=0))
+ array = array[:, column_cumsum.argmin():column_cumsum.argmax() + 2]
+
+ # Remove leading and trailing empty rows but one on each side
+ row_cumsum = numpy.cumsum(numpy.sum(array, axis=1))
+ min_row = row_cumsum.argmin()
+ array = array[min_row:row_cumsum.argmax() + 2, :]
+
+ return array, metrics.ascent() - min_row