2022-04-27 08:42:19 +10:00

572 lines
22 KiB
Python

# SPDX-FileCopyrightText: 2020 Kevin Matocha
#
# SPDX-License-Identifier: MIT
"""
`adafruit_display_text.bitmap_label`
================================================================================
Text graphics handling for CircuitPython, including text boxes
* Author(s): Kevin Matocha
Implementation Notes
--------------------
**Hardware:**
**Software and Dependencies:**
* Adafruit CircuitPython firmware for the supported boards:
https://circuitpython.org/downloads
"""
__version__ = "2.22.3"
__repo__ = "https://github.com/adafruit/Adafruit_CircuitPython_Display_Text.git"
try:
from typing import Union, Optional, Tuple
from fontio import BuiltinFont
from adafruit_bitmap_font.bdf import BDF
from adafruit_bitmap_font.pcf import PCF
except ImportError:
pass
import displayio
from adafruit_display_text import LabelBase
# pylint: disable=too-many-instance-attributes
class Label(LabelBase):
"""A label displaying a string of text that is stored in a bitmap.
Note: This ``bitmap_label.py`` library utilizes a :py:class:`~displayio.Bitmap`
to display the text. This method is memory-conserving relative to ``label.py``.
For further reduction in memory usage, set ``save_text=False`` (text string will not
be stored and ``line_spacing`` and ``font`` are immutable with ``save_text``
set to ``False``).
The origin point set by ``x`` and ``y``
properties will be the left edge of the bounding box, and in the center of a M
glyph (if its one line), or the (number of lines * linespacing + M)/2. That is,
it will try to have it be center-left as close as possible.
:param font: A font class that has ``get_bounding_box`` and ``get_glyph``.
Must include a capital M for measuring character size.
:type font: ~BuiltinFont, ~BDF, or ~PCF
:param str text: Text to display
:param int color: Color of all text in RGB hex
:param int background_color: Color of the background, use `None` for transparent
:param float line_spacing: Line spacing of text to display
:param bool background_tight: Set `True` only if you want background box to tightly
surround text. When set to 'True' Padding parameters will be ignored.
:param int padding_top: Additional pixels added to background bounding box at top
:param int padding_bottom: Additional pixels added to background bounding box at bottom
:param int padding_left: Additional pixels added to background bounding box at left
:param int padding_right: Additional pixels added to background bounding box at right
:param (float,float) anchor_point: Point that anchored_position moves relative to.
Tuple with decimal percentage of width and height.
(E.g. (0,0) is top left, (1.0, 0.5): is middle right.)
:param (int,int) anchored_position: Position relative to the anchor_point. Tuple
containing x,y pixel coordinates.
:param int scale: Integer value of the pixel scaling
:param bool save_text: Set True to save the text string as a constant in the
label structure. Set False to reduce memory use.
:param bool base_alignment: when True allows to align text label to the baseline.
This is helpful when two or more labels need to be aligned to the same baseline
:param (int,str) tab_replacement: tuple with tab character replace information. When
(4, " ") will indicate a tab replacement of 4 spaces, defaults to 4 spaces by
tab character
:param str label_direction: string defining the label text orientation. There are 5
configurations possibles ``LTR``-Left-To-Right ``RTL``-Right-To-Left
``UPD``-Upside Down ``UPR``-Upwards ``DWR``-Downwards. It defaults to ``LTR``"""
# This maps label_direction to TileGrid's transpose_xy, flip_x, flip_y
_DIR_MAP = {
"UPR": (True, True, False),
"DWR": (True, False, True),
"UPD": (False, True, True),
"LTR": (False, False, False),
"RTL": (False, False, False),
}
def __init__(
self, font: Union[BuiltinFont, BDF, PCF], save_text: bool = True, **kwargs
) -> None:
self._bitmap = None
self._tilegrid = None
self._prev_label_direction = None
super().__init__(font, **kwargs)
self._save_text = save_text
self._text = self._replace_tabs(self._text)
# call the text updater with all the arguments.
self._reset_text(
font=font,
text=self._text,
line_spacing=self._line_spacing,
scale=self.scale,
)
def _reset_text(
self,
font: Optional[Union[BuiltinFont, BDF, PCF]] = None,
text: Optional[str] = None,
line_spacing: Optional[float] = None,
scale: Optional[int] = None,
) -> None:
# pylint: disable=too-many-branches, too-many-statements, too-many-locals
# Store all the instance variables
if font is not None:
self._font = font
if line_spacing is not None:
self._line_spacing = line_spacing
# if text is not provided as a parameter (text is None), use the previous value.
if (text is None) and self._save_text:
text = self._text
if self._save_text: # text string will be saved
self._text = self._replace_tabs(text)
else:
self._text = None # save a None value since text string is not saved
# Check for empty string
if (text == "") or (
text is None
): # If empty string, just create a zero-sized bounding box and that's it.
self._bounding_box = (
0,
0,
0, # zero width with text == ""
0, # zero height with text == ""
)
# Clear out any items in the self._local_group Group, in case this is an
# update to the bitmap_label
for _ in self._local_group:
self._local_group.pop(0)
# Free the bitmap and tilegrid since they are removed
self._bitmap = None
self._tilegrid = None
else: # The text string is not empty, so create the Bitmap and TileGrid and
# append to the self Group
# Calculate the text bounding box
# Calculate both "tight" and "loose" bounding box dimensions to match label for
# anchor_position calculations
(
box_x,
tight_box_y,
x_offset,
tight_y_offset,
loose_box_y,
loose_y_offset,
) = self._text_bounding_box(
text,
self._font,
) # calculate the box size for a tight and loose backgrounds
if self._background_tight:
box_y = tight_box_y
y_offset = tight_y_offset
else: # calculate the box size for a loose background
box_y = loose_box_y
y_offset = loose_y_offset
# Calculate the background size including padding
box_x = box_x + self._padding_left + self._padding_right
box_y = box_y + self._padding_top + self._padding_bottom
# Create the Bitmap unless it can be reused
new_bitmap = None
if (
self._bitmap is None
or self._bitmap.width != box_x
or self._bitmap.height != box_y
):
new_bitmap = displayio.Bitmap(box_x, box_y, len(self._palette))
self._bitmap = new_bitmap
else:
self._bitmap.fill(0)
# Place the text into the Bitmap
self._place_text(
self._bitmap,
text if self._label_direction != "RTL" else "".join(reversed(text)),
self._font,
self._padding_left - x_offset,
self._padding_top + y_offset,
)
if self._base_alignment:
label_position_yoffset = 0
else:
label_position_yoffset = self._ascent // 2
# Create the TileGrid if not created bitmap unchanged
if self._tilegrid is None or new_bitmap:
self._tilegrid = displayio.TileGrid(
self._bitmap,
pixel_shader=self._palette,
width=1,
height=1,
tile_width=box_x,
tile_height=box_y,
default_tile=0,
x=-self._padding_left + x_offset,
y=label_position_yoffset - y_offset - self._padding_top,
)
# Clear out any items in the local_group Group, in case this is an update to
# the bitmap_label
for _ in self._local_group:
self._local_group.pop(0)
self._local_group.append(
self._tilegrid
) # add the bitmap's tilegrid to the group
# Set TileGrid properties based on label_direction
if self._label_direction != self._prev_label_direction:
tg1 = self._tilegrid
tg1.transpose_xy, tg1.flip_x, tg1.flip_y = self._DIR_MAP[
self._label_direction
]
# Update bounding_box values. Note: To be consistent with label.py,
# this is the bounding box for the text only, not including the background.
if self._label_direction in ("UPR", "DWR"):
self._bounding_box = (
self._tilegrid.x,
self._tilegrid.y,
tight_box_y,
box_x,
)
else:
self._bounding_box = (
self._tilegrid.x,
self._tilegrid.y,
box_x,
tight_box_y,
)
if (
scale is not None
): # Scale will be defined in local_group (Note: self should have scale=1)
self.scale = scale # call the setter
# set the anchored_position with setter after bitmap is created, sets the
# x,y positions of the label
self.anchored_position = self._anchored_position
@staticmethod
def _line_spacing_ypixels(
font: Union[BuiltinFont, BDF, PCF], line_spacing: float
) -> int:
# Note: Scaling is provided at the Group level
return_value = int(line_spacing * font.get_bounding_box()[1])
return return_value
def _text_bounding_box(
self, text: str, font: Union[BuiltinFont, BDF, PCF]
) -> Tuple[int, int, int, int, int, int]:
# pylint: disable=too-many-locals
ascender_max, descender_max = self._ascent, self._descent
lines = 1
xposition = (
x_start
) = yposition = y_start = 0 # starting x and y position (left margin)
left = None
right = x_start
top = bottom = y_start
y_offset_tight = self._ascent // 2
newline = False
line_spacing = self._line_spacing
for char in text:
if char == "\n": # newline
newline = True
else:
my_glyph = font.get_glyph(ord(char))
if my_glyph is None: # Error checking: no glyph found
print("Glyph not found: {}".format(repr(char)))
else:
if newline:
newline = False
xposition = x_start # reset to left column
yposition = yposition + self._line_spacing_ypixels(
font, line_spacing
) # Add a newline
lines += 1
if xposition == x_start:
if left is None:
left = my_glyph.dx
else:
left = min(left, my_glyph.dx)
xright = xposition + my_glyph.width + my_glyph.dx
xposition += my_glyph.shift_x
right = max(right, xposition, xright)
if yposition == y_start: # first line, find the Ascender height
top = min(top, -my_glyph.height - my_glyph.dy + y_offset_tight)
bottom = max(bottom, yposition - my_glyph.dy + y_offset_tight)
if left is None:
left = 0
final_box_width = right - left
final_box_height_tight = bottom - top
final_y_offset_tight = -top + y_offset_tight
final_box_height_loose = (lines - 1) * self._line_spacing_ypixels(
font, line_spacing
) + (ascender_max + descender_max)
final_y_offset_loose = ascender_max
# return (final_box_width, final_box_height, left, final_y_offset)
return (
final_box_width,
final_box_height_tight,
left,
final_y_offset_tight,
final_box_height_loose,
final_y_offset_loose,
)
def _place_text(
self,
bitmap: displayio.Bitmap,
text: str,
font: Union[BuiltinFont, BDF, PCF],
xposition: int,
yposition: int,
skip_index: int = 0, # set to None to write all pixels, other wise skip this palette index
# when copying glyph bitmaps (this is important for slanted text
# where rectangular glyph boxes overlap)
) -> Tuple[int, int, int, int]:
# pylint: disable=too-many-arguments, too-many-locals
# placeText - Writes text into a bitmap at the specified location.
#
# Note: scale is pushed up to Group level
x_start = xposition # starting x position (left margin)
y_start = yposition
left = None
right = x_start
top = bottom = y_start
line_spacing = self._line_spacing
for char in text:
if char == "\n": # newline
xposition = x_start # reset to left column
yposition = yposition + self._line_spacing_ypixels(
font, line_spacing
) # Add a newline
else:
my_glyph = font.get_glyph(ord(char))
if my_glyph is None: # Error checking: no glyph found
print("Glyph not found: {}".format(repr(char)))
else:
if xposition == x_start:
if left is None:
left = my_glyph.dx
else:
left = min(left, my_glyph.dx)
right = max(
right,
xposition + my_glyph.shift_x,
xposition + my_glyph.width + my_glyph.dx,
)
if yposition == y_start: # first line, find the Ascender height
top = min(top, -my_glyph.height - my_glyph.dy)
bottom = max(bottom, yposition - my_glyph.dy)
glyph_offset_x = (
my_glyph.tile_index * my_glyph.width
) # for type BuiltinFont, this creates the x-offset in the glyph bitmap.
# for BDF loaded fonts, this should equal 0
y_blit_target = yposition - my_glyph.height - my_glyph.dy
# Clip glyph y-direction if outside the font ascent/descent metrics.
# Note: bitmap.blit will automatically clip the bottom of the glyph.
y_clip = 0
if y_blit_target < 0:
y_clip = -y_blit_target # clip this amount from top of bitmap
y_blit_target = 0 # draw the clipped bitmap at y=0
print(
'Warning: Glyph clipped, exceeds Ascent property: "{}"'.format(
char
)
)
if (y_blit_target + my_glyph.height) > bitmap.height:
print(
'Warning: Glyph clipped, exceeds descent property: "{}"'.format(
char
)
)
self._blit(
bitmap,
xposition + my_glyph.dx,
y_blit_target,
my_glyph.bitmap,
x_1=glyph_offset_x,
y_1=y_clip,
x_2=glyph_offset_x + my_glyph.width,
y_2=my_glyph.height,
skip_index=skip_index, # do not copy over any 0 background pixels
)
xposition = xposition + my_glyph.shift_x
# bounding_box
return left, top, right - left, bottom - top
def _blit(
self,
bitmap: displayio.Bitmap, # target bitmap
x: int, # target x upper left corner
y: int, # target y upper left corner
source_bitmap: displayio.Bitmap, # source bitmap
x_1: int = 0, # source x start
y_1: int = 0, # source y start
x_2: int = None, # source x end
y_2: int = None, # source y end
skip_index: int = None, # palette index that will not be copied
# (for example: the background color of a glyph)
) -> None:
# pylint: disable=no-self-use, too-many-arguments
if hasattr(bitmap, "blit"): # if bitmap has a built-in blit function, call it
# this function should perform its own input checks
bitmap.blit(
x,
y,
source_bitmap,
x1=x_1,
y1=y_1,
x2=x_2,
y2=y_2,
skip_index=skip_index,
)
else: # perform pixel by pixel copy of the bitmap
# Perform input checks
if x_2 is None:
x_2 = source_bitmap.width
if y_2 is None:
y_2 = source_bitmap.height
# Rearrange so that x_1 < x_2 and y1 < y2
if x_1 > x_2:
x_1, x_2 = x_2, x_1
if y_1 > y_2:
y_1, y_2 = y_2, y_1
# Ensure that x2 and y2 are within source bitmap size
x_2 = min(x_2, source_bitmap.width)
y_2 = min(y_2, source_bitmap.height)
for y_count in range(y_2 - y_1):
for x_count in range(x_2 - x_1):
x_placement = x + x_count
y_placement = y + y_count
if (bitmap.width > x_placement >= 0) and (
bitmap.height > y_placement >= 0
): # ensure placement is within target bitmap
# get the palette index from the source bitmap
this_pixel_color = source_bitmap[
y_1
+ (
y_count * source_bitmap.width
) # Direct index into a bitmap array is speedier than [x,y] tuple
+ x_1
+ x_count
]
if (skip_index is None) or (this_pixel_color != skip_index):
bitmap[ # Direct index into a bitmap array is speedier than [x,y] tuple
y_placement * bitmap.width + x_placement
] = this_pixel_color
elif y_placement > bitmap.height:
break
def _set_line_spacing(self, new_line_spacing: float) -> None:
if self._save_text:
self._reset_text(line_spacing=new_line_spacing, scale=self.scale)
else:
raise RuntimeError("line_spacing is immutable when save_text is False")
def _set_font(self, new_font: Union[BuiltinFont, BDF, PCF]) -> None:
self._font = new_font
if self._save_text:
self._reset_text(font=new_font, scale=self.scale)
else:
raise RuntimeError("font is immutable when save_text is False")
def _set_text(self, new_text: str, scale: int) -> None:
self._reset_text(text=self._replace_tabs(new_text), scale=self.scale)
def _set_background_color(self, new_color: Optional[int]):
self._background_color = new_color
if new_color is not None:
self._palette[0] = new_color
self._palette.make_opaque(0)
else:
self._palette[0] = 0
self._palette.make_transparent(0)
def _set_label_direction(self, new_label_direction: str) -> None:
self._prev_label_direction = self._label_direction
self._label_direction = new_label_direction
self._reset_text(text=str(self._text)) # Force a recalculation
def _get_valid_label_directions(self) -> Tuple[str, ...]:
return "LTR", "RTL", "UPD", "UPR", "DWR"
@property
def bitmap(self) -> displayio.Bitmap:
"""
The Bitmap object that the text and background are drawn into.
:rtype: displayio.Bitmap
"""
return self._bitmap