UbuntuWebView doesn't regard GRID_UNIT_PX

[Michael Zanetti]

On High-DPI screens like the Apple Retina Display all Ubuntu Components and apps adjust nicely to the DPI by setting the GRID_UNIT_PX env variable. One exception to this is the UbuntuWebView which loads websites very, very tiny on such displays, regardless of the used GRID_UNIT_PX value.

The WebView has it's own env variable, QTWEBKIT_DPR, which allows adjusting it's resolution. However, this isn't obvious to users and especially on desktop systems QTWEBKIT_DPR is mostly not set to anything.

Couldn't we initialize QTWEBKIT_DPR to a sane value calculated from the GRID_UNIT_PX value in case it is not explicitly set?

[Olivier Tilloy (osomon)]

From our IRC discussion:

    <mzanetti> I'm using 20 px/gu and it seems a DPR value of 4 fits nicely
      on the apple retina display that is

On my galaxy Nexus, GRID_UNIT_PX=18 and QTWEBKIT_DPR=2.0

So unfortunately there doesn’t seem to be a direct proportional relationship between GRID_UNIT_PX and QTWEBKIT_DPR.
This very probably depends on the density of the display.

[Olivier Tilloy (osomon)]

Note that on my desktop (1920×1080 external monitor plugged to my laptop, not high density), I’m using the default values for both environment variables (GRID_UNIT_PX=8 and QTWEBKIT_DPR=1.0) and content in the browser looks good.

[Olivier Tilloy (osomon)]

@Michael: would you mind testing again with the latest version (import Ubuntu.Web 0.2 and instantiate a WebView)?

Since the issue was originally reported, we switched from QtWebKit to oxide, and I believe it may have made things better on this front.

[Olivier Tilloy (osomon)]

Michael, is this still valid? Can you confirm/invalidate please?

[Michael Zanetti (mzanetti)]

Hi Olivier,

Here's a screenshot using a test app with Ubuntu.Web 0.2:

http://i.imgur.com/E6Hzq8s.png

On the left, started with GRID_UNIT_PX=8, on the right with GRID_UNIT_PX=16

So looks to me as this is still valid.

[Christopher Kyle Horton (christhehorton)]

Is this the bug I'm looking for? I was going to report that the Ubuntu web browser app does not respect the display scaling set in the System Settings on Wily (Unity 7 desktop image), but I'm not sure if this is already reported. Text in the browser / Unity web apps appears very small without the scaling support, making it hard to read on my Lenovo Yoga.

[Olivier Tilloy (osomon)]

Christopher: that would be a different issue. Unity 7 doesn’t care about GRID_UNIT_PX.