Metadata-Version: 2.1
Name: epdlib
Version: 0.4.2
Summary: EpdLib is a library for creating dynamically scaled screen layouts for frame-buffered devices such as e-paper/e-ink displays.
Home-page: https://github.com/txoof/epdlib
Author: Aaron Ciuffo
Author-email: aaron.ciuffo@gmail.com
License: UNKNOWN
Project-URL: Source, https://github.com/txoof/epdlib
Keywords: graphics e-paper display waveshare
Platform: UNKNOWN
Classifier: Intended Audience :: Developers
Classifier: Topic :: Software Development :: Libraries :: Python Modules
Classifier: Programming Language :: Python :: 3.7
Classifier: License :: OSI Approved :: GNU General Public License v3 or later (GPLv3+)
Classifier: Operating System :: OS Independent
Requires-Python: >=3.7
Description-Content-Type: text/markdown
License-File: LICENSE

# epdlib v0.4
EpdLib is a library for creating dynamically scaled screen layouts for frame-buffered devices such as e-paper/e-ink displays. Complex layouts are defined as image or text blocks. Using epdlib blocks makes it trivial to develop for different disiplay resolutions as layouts are aware of thier resolution and scale the blocks dynamically to match the available area.

## Changes
**Screen**

* now supports IT9851 based panels
* `Screen.epd` object is now supplied as a string, not an object
    - use `epdlib.Screen.list_compatible_modules()` to show compatible waveshare_epd panels
    - use `Screen(epd='HD', vcom=[your IT9851 vcom (see ribon cable)]` for IT8951 based panels
* `Screen.writeEPD()` now supports partial refresh on IT9851 panels for partial refresh of black & white pixels
    - use `writeEPD(image, partial=True)`
    - partial refresh does not affect gray pixels


**Block**

* now supports 8 bit grayscale images, text and background on IT8951 based panels
    - previously 8 bit images were downscaled to dithered 1 bit images; this is still the case on 1 bit panels
    - use `Block.mode = "L"` for 8 bit support within a block
* now supports 8 bit fill and background on IT8951 panels
    - use `Block.background=[0-255]` and `Block.fill=[0-255]` 0 is black, 255 is fully white
* padding now fully supported in all block types
    - previosuly only worked properly on `ImageBlock` objects

**Layout**
* now supports the following features when specified in the layout dictionary:
    - `'fill': 0-255` specify text fill (8 bit gray 0 is black)
    - `'bkground: 0-255` specify background color (8 bit gray 0 is black)
    - `'mode': "L"/"1"` specify block image mode "L" 8 bit, "1" 1 bit

## Dependencies
Python Modules:
* Pillow
    - System dependencies for Pillow:
        * libopenjp2-7
        * libtiff5
* RPi.GPIO
* spidev
    - ensure SPI is enabled on the pi
* waveshare-epd (Non IT8951 based panels)
    - this is for interacting with waveshare epaper displays and is not strictly needed to use the Block and Layout objects.
    - see [notes](#Notes) below for installation instructions
* IT8951 (IT8951 based panels)
    - see [notes](#Notes) below for installation instructions



**Modules:**
* [Block](#Block) - image and text blocks that can be assembed into a final layout
* [Layout](#Layout) - generate dynamic layouts from Blocks
* [Screen](#Screen) - simple interface for waking and writing to WaveShare EPD devices

<a name="Block"></a>
## Block Module
`Block` objects are containers for text and images. `Block` objects are aware of their dimensions and can be made aware of their position within a larger layout. `Block` objects can also handle wrapping text and resizing images to fit within their borders.
*Class* `Block(area, hcenter=False, vcenter=False, rand=False, inverse=False, abs_coordinates=(0, 0), padding=0)`

### Properties
        
Parent class for other types of blocks

Args [default value]: 
 *  `area`(list/tuple): x and y integer values for dimensions of block area
 *  `hcenter`(bool): True: horizontally center contents [False]
 *  `vcenter`(bool): True: vertically center contents [False]
 *  `rand`(bool): True: randomly place contents in area [False]
 *  `inverse`(bool): True: invert pixel values [False]
 *  `abs_coordinates`(list/tuple): x, y integer coordinates of this block area
    within a larger image [(0, 0)]
 *  `padding`(int): number of pixels to pad around edge of contents [0]
 *  `fill`(int): 0-255 8 bit value for fill color for text/images [0 black]
 *  `bkground`(int): 0-255 8 bit value for background color [255 white]
 *  `mode`(str): '1': 1 bit color, 'L': 8 bit grayscale ['1']

Properties:
 *  `image`: None - overridden in child classes'''

### Methods
`update(update)`
Place holder method for child classes.
 

## Block.TextBlock
Child class of `Block` that contains formatted text. `TextBlock` objects can do basic formatting of strings. Text is always rendered as a 1 bit image (black on white or white on black). Text can be horizontally justified and centered and vertically centered within the area of the block. 

All properties of the parent class are inherited.

*Class* `Block.TextBlock(font, area, text='NONE', font_size=0, max_lines=1, maxchar=None, chardist=None)`

`TextBlock` objects will attempt to calculate the appropriate number of characters to render on each line given an area, font face and character distribution. Each font face renders characters at a different width and each TTF character uses a different X width (excluding fixed-width fonts). Each language favors certain characters over others. 

### Properties
* `font` (str): path to TTF font face - relative paths are acceptable
* `area` (2-tuple of int): area of block in pixles - required
* `text` (str): string to format 
    - Default: 'NONE'
* `font_size` (int): font size in points
    - Default: 0
* `max_lines` (int): maximum number of lines to use when wrapping text
    - Default: 1
* `maxchar` (int): maximum number of characters to fit on a line
    - if set to `None`, the text block will calculate this value based on the font face and specified `chardist`
    - Default: None
* `chardist` (dict): statistical character distribution for a supported language to use for a specified font
    - dictionary of letter and float representing fractional distribution (see `print_chardist`)
* `image` (PIL.Image): resultant image generated of formatted text

### Functions
* `print_chardist(chardist=None)` - print supported character distrubtions
    - chardist (str)
        - `chardist='USA_CHARDIST'` print the character distribution for USA English

### Methods
* `update(update=None)` - Update the text string with a new string and sets `image` property
    - update (str)

## Block.ImageBlock
Child class of `Block` that contains formated images. `ImageBlock` objects do basic formatting of color, centering and scaling. All `ImageBlock` images are 8 bit grayscale `Pillow.Image(mode='L')`. Images that are too large for the area are rescaled using the `Pillow.Image.thumbnail()` strageies to limit distortion. Images that are smaller than the set area will **not** be resized.

All properties of the parent class are inherited.

*Class* `Block.ImageBlock(area, image=None)`

### Properties
* `image` (:obj:PIL.Image or :obj:str) - `Pillow` image or path provided as a `str` to an image file; relative paths are acceptable

<a name="Layout"></a>
## Layout Module
`Layout` objects support scaling images and dynamically scaling [TTF](https://en.wikipedia.org/wiki/TrueType) font-size for different screen sizes. 

Font sizes are set based on each individual font and scaled to fit within text blocks using the maximum number of lines specified in the layout. Text is line-broken using the python [textwrap logic](https://docs.python.org/3.7/library/textwrap.html).

*Class* `Layout(resolution, layout=None)`

## Scaling Example
epdlib `Layout` objects can be scaled to any (reasonable) resolution while maintaining internally consistent ratios.

**500x500 Layout**

![500x500 weather image](./docs/weather_5x5.png)

**300x200 Layout**
![300x200 weather_image](./docs/weather_3x2.png)


### Properties
* `resolution` (2-tuple of int): resolution of the entire screen in pixles
* `layout` (dict): dictionary containing layout paramaters for each block
    - see example below in Quick-Start Recipe
* `image` (Pil.Image): concatination of all blocks into single image

### Methods
* `concat()`: join all blocks into a single image
    - sets `image` property
* `update_contents(updates=None)` - update the contents of each block
    - updates (dict)
        - dictionary in the format `{'text_section': 'text to use', 'image_section': '/path/to/img', 'pil_img_section': PIL.Image}`

<a name="Screen"></a>
## Screen Module
`Screen` objects provide a method for waking and writing to a WaveShare E-Paper Display (EPD). `Screen` objects are aware of their resolution and when they were last updated (stored in monotonic time). 

*Class* `Screen(resolution=None, epd=None)`

### Properties
* `resolution` (2 tuple of int): resolution in pixels 
    - this is overriden by the epd object resolution when it is set
* `epd` (epd object)
    - waveshare epd object used for interfacing with the display
* `update` (obj:Screen.Update): monotonicly aware object that tracks time since last update
* `rotation` (int): [-90, 0, 90, 180, 270] rotation of screen 
* `mode`(str): '1' for 1 bit screens, 'L' for screens capable of 8 bit grayscale
* `vcom`(float): vcom voltage for HD IT8951 based screens (not needed & ignored for non-HD screens)


### Methods
* `clearScreen()`: Set a blank image screen
* `clearEPD()`: send the clear signal to the EPD to wipe all contents and set to "white"
* `writeEPD(image, sleep=True, partial=False)`: write `image` to the EPD. 
    - resets update timer
    - sleep: put the display to low power mode (default: True)
    - partial: update only chaged portions of the screen (faster, but only works with black and white pixles) (default: False)
* `intiEPD()` - initializes the EPD for writing
* `blank_image():` produces a blank PIL.Image in of `mode` type of `resolution` dimensions
* `list_compatible_modules()`: print a list of all waveshare_epd panels that are compatible with paperpi

### Example
```
import Screen
import waveshare_epd
myScreen = Screen()
myScreen.epd = "epd5in83"
myScreen.initEPD()
myScreen.writeEPD('./my_image.png')
```


## Screen.Update
Create a monotonically aware object that records the passage of time.

*Class* `Screen.Update()`

### Properties
* `age` (float): age in seconds since creation
* `now` (float): time in [CLOCK_MONOTONIC](https://linux.die.net/man/3/clock_gettime) time
* `last_updated` (float): time in seconds since last updated
* `update` (bool): True - trigger resets last_updated time

### Methods
* `update(update=True)` - reset last_updated timer to zero

### Example
```
import Screen
u = Update()
u.now
>>> 357147.118559987
u.age
>>> 37.449310125026386
u.last_updated
>>> 62.2587232599617
u.update = True
u.last_updated
>>> 0.00021347898291423917
```

## Screen.ScreenShot
Capture a rolling set of screenshots. When the total number of screenshots exceeds `n` the oldest is deleted. Images are stored as .png.

This is useful for debugging over time.

*Class* `Screen.ScreenShot(path='./', n=2, prefix=None)`

### Properties
* `total` (int): total number of screenshots to keep
* `prefix` (str): prefix to add to filenames
* `time` (str): time in format: %y-%m-%d_%H%M.%S - 2020-02-29_1456.39
* `img_array` (list): list of files stored in `path`

### Methods
* `delete(img)`: delete `img` file
* `save(img)`: save `img` to `path`
    - img: PIL.Image
```
import Screen
scrnShot = Screen.ScreenShot(path='/temp/', n=20)
spam = PIL.Image.new(mode='L', size=(100, 100), color=0)
scrnShot.save(spam)
```

## Quick-Start Recipe
The following recipe will produce the screen layout shown above for a 640x400 pixel display. This image can be passed directly to a WaveShare e-Paper display for writing.

### Creating an Image from a Layout
```
import epdlib

# create the layout object - adjust the resolution to match the display area
layout_obj = epdlib.Layout(resolution=(640, 400))

l = { # basic two row layout
    'tux_img': {                
            'image': True,               # image block
            'padding': 10,               # pixels to padd around edge
            'width': 1/4,                # 1/4 of the entire width
            'height': 1/4,               # 1/4 of the entire height
            'abs_coordinates': (0, 0),   # this block is the key block that all other blocks will be defined in terms of
            'hcenter': True,             # horizontally center image
            'vcenter': True,             # vertically center image
            'relative': False,           # this block is not relative to any other. It has an ABSOLUTE position (0, 0)
            'mode': 'L',                 # treat this image as an 8bit gray-scale image
        },
    'pangram_a': { 
                'image': None,           # set to None if this is a text block
                'max_lines': 3,          # maximum lines of text to use when wrapping text
                'padding': 10,           # padding around all edges (in pixles)
                'width': 3/4,            # proportion of the entire width
                'height': 1/4,           # proprtion of the entire height
                'abs_coordinates': (None, 0), # absolute coordinates within the final image (use None for those
                                              # coordinates that are relative to other blocks and will be calculated
                'hcenter': False,         # horizontal-center the text and the resulting image
                'vcenter': True,         # vertically-center the text within the block
                'relative': ['tux_img', 'pangram_a'], # blocks to which THIS block's coordinates are relative to
                                                            # -- in this case X: `weather_img` and Y: `temperature`
                                                            # the width of the block `weather` will be used to
                                                            # to calculate the X value of this block and the Y value
                                                            # specified within the `temperature` block will be used 
                'font': './fonts/Open_Sans/OpenSans-Regular.ttf', # TTF Font face to use; relative paths are OK
                'font_size': None         # set this to None to automatically scale the font to the size of the block
    },
    'pangram_b': { 
                'image': None,
                'max_lines': 2,
                'padding': 0,
                'width': 1,
                'height': 1/4,
                'abs_coordinates': (0, None),
                'hcenter': True,
                'vcenter': True,
                'relative': ['pangram_b', 'tux_img'],
                'font': './fonts/Open_Sans/OpenSans-Regular.ttf',
                'font_size': None,
                'inverse': True
    },
    'pangram_c': { 
                'image': None,
                'max_lines': 3,
                'padding': 0,
                'width': 1,
                'height': 1/4,
                'abs_coordinates': (0, None),
                'hcenter': True,
                'vcenter': False,
                'relative': ['pangram_c', 'pangram_b'],
                'font': './fonts/Open_Sans/OpenSans-BoldItalic.ttf',
                'font_size': None,
                'inverse': False,
    },    
    'text': {
                'image': None,
                'max_lines': 3,
                'padding': 10,
                'width': 1,
                'height': 1/4,
                'abs_coordinates': (0, None),
                'hcenter': False,
                'vcenter': True,
                'relative': ['text', 'pangram_c'],
                'font': './fonts/Open_Sans/OpenSans-Regular.ttf',
                'font_size': None,
                'inverse': True
    }

}

# apply the layout instructions to the layout object
layout_obj.layout = l

# create a dictionary with the values that will be pushed to each block
update = {
    'tux_img': './images/tux.png',      
    'pangram_a': 'The quick brown fox jumps over the lazy dog.',  
    'pangram_b': 'Pack my box with five jugs of liquor.',          
    'pangram_c': 'Jackdaws love my big sphinx of quartz.',                    
    'text': 'A pangram or holoalphabetic sentence is a sentence using every letter of a given alphabet at least once. '}

# update the layout with the data in the dictionary and send each item to the proper block
layout_obj.update_contents(update)

# join all the sub images into one complete image
myImg = layout_obj.concat()
# write the image out to a file
myImg.save('sample.jpg')

```
<a name="Notes"></a>
## Notes
The Waveshare-epd library is provided only as a git repo. Try the following to install it:

```
pipenv install -e "git+https://github.com/waveshare/e-Paper.git#egg=waveshare_epd&subdirectory=RaspberryPi_JetsonNano/python"
```

The IT8951 library is provided only as a git repo. Try the following ot install it:
```
pipenv install -e "git+https://github.com/GregDMeyer/IT8951#egg=IT8951"
```

getting ready for pypi:
https://medium.com/@joel.barmettler/how-to-upload-your-python-package-to-pypi-65edc5fe9c56


```python
!jupyter-nbconvert --to markdown --stdout readme_inprogress.ipynb > README.md
```


