diff options
| -rw-r--r-- | crocoite/behavior.py | 48 | ||||
| -rw-r--r-- | crocoite/data/screenshot.js | 20 |
2 files changed, 57 insertions, 11 deletions
diff --git a/crocoite/behavior.py b/crocoite/behavior.py index bdae5f9..fd4d066 100644 --- a/crocoite/behavior.py +++ b/crocoite/behavior.py @@ -279,40 +279,66 @@ class Screenshot (Behavior): Create screenshot from tab and write it to WARC """ + __slots__ = ('script') + name = 'screenshot' # Hardcoded max texture size of 16,384 (crbug.com/770769) maxDim = 16*1024 + def __init__ (self, loader, logger): + super ().__init__ (loader, logger) + self.script = Script ('screenshot.js') + async def onfinish (self): tab = self.loader.tab + # for top-level/full-screen elements with position: fixed we need to + # figure out their actual size (i.e. scrollHeight) and use that when + # overriding the viewport size. + # we could do this without javascript, but that would require several + # round-trips to Chrome or pulling down the entire DOM+computed styles + tab = self.loader.tab + yield self.script + result = await tab.Runtime.evaluate (expression=str (self.script), returnByValue=True) + assert result['result']['type'] == 'object', result + result = result['result']['value'] + # this is required to make the browser render more than just the small # actual viewport (i.e. entire page). see # https://github.com/GoogleChrome/puppeteer/blob/45873ea737b4ebe4fa7d6f46256b2ea19ce18aa7/lib/Page.js#L805 metrics = await tab.Page.getLayoutMetrics () contentSize = metrics['contentSize'] - - await tab.Emulation.setDeviceMetricsOverride ( - width=0, height=0, deviceScaleFactor=0, mobile=False, - viewport={'x': 0, - 'y': 0, - 'width': contentSize['width'], - 'height': contentSize['height'], - 'scale': 1}) + contentHeight = max (result + [contentSize['height']]) + + override = { + 'width': 0, + 'height': 0, + 'deviceScaleFactor': 0, + 'mobile': False, + 'viewport': {'x': 0, + 'y': 0, + 'width': contentSize['width'], + 'height': contentHeight, + 'scale': 1} + } + self.logger.debug ('screenshot override', + uuid='e0affa18-cbb1-4d97-9d13-9a88f704b1b2', override=override) + await tab.Emulation.setDeviceMetricsOverride (**override) tree = await tab.Page.getFrameTree () try: url = URL (tree['frameTree']['frame']['url']).with_fragment (None) except KeyError: - self.logger.error ('frame without url', tree=tree) + self.logger.error ('frame without url', + uuid='edc2743d-b93e-4ba1-964e-db232f2f96ff', tree=tree) url = None width = min (contentSize['width'], self.maxDim) # we’re ignoring horizontal scroll intentionally. Most horizontal # layouts use JavaScript scrolling and don’t extend the viewport. - for yoff in range (0, contentSize['height'], self.maxDim): - height = min (contentSize['height'] - yoff, self.maxDim) + for yoff in range (0, contentHeight, self.maxDim): + height = min (contentHeight - yoff, self.maxDim) clip = {'x': 0, 'y': yoff, 'width': width, 'height': height, 'scale': 1} ret = await tab.Page.captureScreenshot (format='png', clip=clip) data = b64decode (ret['data']) diff --git a/crocoite/data/screenshot.js b/crocoite/data/screenshot.js new file mode 100644 index 0000000..a9a41e1 --- /dev/null +++ b/crocoite/data/screenshot.js @@ -0,0 +1,20 @@ +/* Find and scrollable full-screen elements and return their actual size + */ +(function () { +/* limit the number of elements queried */ +let elem = document.querySelectorAll ('body > div'); +let ret = []; +for (let i = 0; i < elem.length; i++) { + let e = elem[i]; + let s = window.getComputedStyle (e); + if (s.getPropertyValue ('position') == 'fixed' && + s.getPropertyValue ('overflow') == 'auto' && + s.getPropertyValue ('left') == '0px' && + s.getPropertyValue ('right') == '0px' && + s.getPropertyValue ('top') == '0px' && + s.getPropertyValue ('bottom') == '0px') { + ret.push (e.scrollHeight); + } +} +return ret; /* immediately return results, for use with Runtime.evaluate() */ +})(); |