Tests for WBE Chapter 3
=======================
Chapter 3 (Formatting Text) adds on font metrics and simple font styling via
HTML tags. This file contains tests for the additional functionality.
>>> import wbemocks
>>> _ = wbemocks.socket.patch().start()
>>> _ = wbemocks.ssl.patch().start()
>>> import browser
Make sure you have the expected default values for `HSTEP`, `VSTEP`,
`WIDTH`, and `HEIGHT`.
>>> browser.HSTEP
13
>>> browser.VSTEP
18
>>> browser.WIDTH
800
>>> browser.HEIGHT
600
Notes
=====
You might need to modify the `__repr__` method on `Text` and `Tag`
if you factored your project into multiple files: (This is especially
true if you see a mismatched output of the form `<layout.Tag object at ...>`)
```
class Text:
...
def __repr__(self):
return "Text('{}')".format(self.text)
class Tag:
...
def __repr__(self):
return "Tag('{}')".format(self.tag)
```
Testing `lex`
-------------
The `lex` function in chapter three has been beefed up to return an array
of `Tag` or `Text` objects, rather than just the stream of characters from the
input.
To allow us to print these in a readable form please add a `__repr__(self):` method
to your `Tag` and `Text` classes.
The bodies of these methods should, respectively, be
`return "Tag('{}')".format(self.tag)`
and `return "Text('{}')".format(self.text)`
>>> browser.lex('<body>hello</body>')
[Tag('body'), Text('hello'), Tag('/body')]
>>> browser.lex('he<body>llo</body>')
[Text('he'), Tag('body'), Text('llo'), Tag('/body')]
>>> browser.lex('he<body>l</body>lo')
[Text('he'), Tag('body'), Text('l'), Tag('/body'), Text('lo')]
>>> browser.lex('he<body>l<div>l</div>o</body>')
[Text('he'), Tag('body'), Text('l'), Tag('div'), Text('l'), Tag('/div'), Text('o'), Tag('/body')]
Note that the tags do not have to match:
>>> browser.lex('he<body>l</div>lo')
[Text('he'), Tag('body'), Text('l'), Tag('/div'), Text('lo')]
>>> browser.lex('he<body>l<div>l</body>o</div>')
[Text('he'), Tag('body'), Text('l'), Tag('div'), Text('l'), Tag('/body'), Text('o'), Tag('/div')]
Testing `Layout`
----------------
This chapter also creates a Layout class to output a display list that can
format text. However, note that this test doesn't use real tkinter fonts, but
rather a mock font that has faked metrics.
>>> def test_layout(text):
... dl = browser.Layout(browser.lex(text)).display_list
... return wbemocks.normalize_display_list(dl)
>>> test_layout("abc")
[(13.0, 21.0, 'abc', Font size=16 weight=normal slant=roman style=None)]
>>> test_layout("<b>abc</b>")
[(13.0, 21.0, 'abc', Font size=16 weight=bold slant=roman style=None)]
>>> test_layout("<big>abc</big>")
[(13.0, 21.75, 'abc', Font size=20 weight=normal slant=roman style=None)]
>>> test_layout("<big><big>abc</big></big>")
[(13.0, 22.5, 'abc', Font size=24 weight=normal slant=roman style=None)]
>>> test_layout("<big><big><i>abc</i></big></big>")
[(13.0, 22.5, 'abc', Font size=24 weight=normal slant=italic style=None)]
>>> test_layout("<big><big><i>abc</i></big>def</big>") #doctest: +NORMALIZE_WHITESPACE
[(13.0, 22.5, 'abc', Font size=24 weight=normal slant=italic style=None),
(109.0, 25.5, 'def', Font size=20 weight=normal slant=roman style=None)]
Lines of text are spaced to make room for the tallest text. Let's lay
out text with mixed font sizes, and then measure the line heights:
>>> def baseline(word):
... return word[1] + word[3].metrics("ascent")
>>> test_layout("Start<br>Regular<br>Regular <big><big>Big") #doctest: +NORMALIZE_WHITESPACE
[(13.0, 21.0, 'Start', Font size=16 weight=normal slant=roman style=None),
(13.0, 41.0, 'Regular', Font size=16 weight=normal slant=roman style=None),
(13.0, 68.5, 'Regular', Font size=16 weight=normal slant=roman style=None),
(141.0, 62.5, 'Big', Font size=24 weight=normal slant=roman style=None)]
>>> display_list = test_layout("Start<br>Regular<br>Regular <big><big>Big")
>>> baseline(display_list[1]) - baseline(display_list[0])
20.0
>>> baseline(display_list[3]) - baseline(display_list[1])
27.5
The differing line heights don't occur when text gets smaller:
>>> test_layout("Start<br>Regular<br>Regular <small><small>Small") #doctest: +NORMALIZE_WHITESPACE
[(13.0, 21.0, 'Start', Font size=16 weight=normal slant=roman style=None),
(13.0, 41.0, 'Regular', Font size=16 weight=normal slant=roman style=None),
(13.0, 61.0, 'Regular', Font size=16 weight=normal slant=roman style=None),
(141.0, 64.0, 'Small', Font size=12 weight=normal slant=roman style=None)]
>>> display_list = test_layout("Start<br>Regular<br>Regular <small><small>Small")
>>> baseline(display_list[1]) - baseline(display_list[0])
20.0
>>> baseline(display_list[3]) - baseline(display_list[1])
20.0
Testing `Browser`
-----------------
Now let's test integration of layout into the Browser class.
>>> url = 'http://wbemocks.test/chapter3-example1'
>>> wbemocks.socket.respond_200(url=url,
... body="<small>abc<i>def</i></small>")
>>> this_browser = browser.Browser()
>>> this_browser.load(browser.URL(url))
Testing the display list output of this URL:
>>> wbemocks.normalize_display_list(this_browser.display_list) #doctest: +NORMALIZE_WHITESPACE
[(13.0, 20.625, 'abc', Font size=14 weight=normal slant=roman style=None),
(69.0, 20.625, 'def', Font size=14 weight=normal slant=italic style=None)]
And the canvas:
>>> wbemocks.patch_canvas()
>>> this_browser = browser.Browser()
>>> this_browser.load(browser.URL(url))
create_text: x=13 y=20.625 text=abc font=Font size=14 weight=normal slant=roman style=None anchor=nw
create_text: x=69 y=20.625 text=def font=Font size=14 weight=normal slant=italic style=None anchor=nw
>>> wbemocks.unpatch_canvas()