Merge pull request #99 from FoamyGuy/wrapping

Wrapping helper function

Author: makermelissa

adafruit_display_text/__init__.py

@@ -0,0 +1,69 @@
+"""
+Display Text module helper functions
+"""
+
+
+# The MIT License (MIT)
+#
+# Copyright (c) 2020 Tim C for Adafruit Industries LLC
+#
+# 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.
+
+
+def wrap_text_to_lines(string, max_chars):
+    """wrap_text_to_lines function
+    A helper that will return a list of lines with word-break wrapping
+
+    :param str string: The text to be wrapped
+    :param int max_chars: The maximum number of characters on a line before wrapping
+
+    :return list the_lines: A list of lines where each line is separated based on the amount
+        of max_chars provided
+
+    """
+
+    def chunks(lst, n):
+        """Yield successive n-sized chunks from lst."""
+        for i in range(0, len(lst), n):
+            yield lst[i : i + n]
+
+    string = string.replace("\n", "").replace("\r", "")  # Strip confusing newlines
+    words = string.split(" ")
+    the_lines = []
+    the_line = ""
+    for w in words:
+        if len(w) > max_chars:
+            parts = []
+            for part in chunks(w, max_chars - 1):
+                parts.append("{}-".format(part))
+            the_lines.extend(parts[:-1])
+            the_line = parts[-1][:-1]
+            continue
+
+        if len(the_line + " " + w) <= max_chars:
+            the_line += " " + w
+        else:
+            the_lines.append(the_line)
+            the_line = "" + w
+    if the_line:  # Last line remaining
+        the_lines.append(the_line)
+    # Remove first space from first line:
+    if the_lines[0][0] == " ":
+        the_lines[0] = the_lines[0][1:]
+    return the_lines

examples/display_text_wraptest.py

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+"""
+This example illustrates how to use the wrap_text_to_lines
+helper function.
+"""
+import board
+import terminalio
+from adafruit_display_text import label, wrap_text_to_lines
+
+# use built in display (PyPortal, PyGamer, PyBadge, CLUE, etc.)
+# see guide for setting up external displays (TFT / OLED breakouts, RGB matrices, etc.)
+# https://learn.adafruit.com/circuitpython-display-support-using-displayio/display-and-display-bus
+display = board.DISPLAY
+
+text = (
+    "Lorem ipsum dolor sit amet, consectetur adipiscing elit, "
+    "sed do eiusmod tempor incididunt ut labore et dolore magna "
+    "aliqua. Ut enim ad minim veniam, quis nostrud exercitation "
+    "ullamco laboris nisi ut aliquip ex ea commodo consequat."
+)
+text = "\n".join(wrap_text_to_lines(text, 28))
+text_area = label.Label(terminalio.FONT, text=text)
+text_area.x = 10
+text_area.y = 10
+display.show(text_area)
+while True:
+    pass