Window.zoomLevel is arbitrary

[M-Pixel]

The wiki currently states

Window.zoomLevel
since v0.4.1

Get or Set the page zoom. 0 for normal size; positive value for zooming in; negative value for zooming out.

It seems to me that "default" should be 1, for 100%. How do I zoom to 150%? Is it 0.5? How do I zoom to 50%, -0.5? Neither would make sense.

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[JovankaB]

I agree, it would be more intuitive. Also you would be able to do something like win.zoomLevel *= 2; to double the zoom level regardless of the current zoom. Right now it seems to be impossible. You can set some number, but it's not clear what is the current zoom level in percentage.

[kitingChris]

Well very sad this is not clarified...
I want to work as well with the zoomLevel but there is a quite lack of information about it :(

[kingslou]

为什么总是自动发邮箱邮件啊 好烦人啊

[rogerwang]

The actual zoom factor = pow(1.2, L) or 1.2^L where L is the zoom level.

See https://github.com/nwjs/blink/blob/2664bfe8de3a82d3d808cd13e8bcb209a01c8232/Source/web/WebViewImpl.cpp#L2827

[kitingChris]

Great thanks. But might it be possible to use a more familiar percentage zoom solution? In my opinion that might be a better option cause css standard also uses percentage.

[loveencounterflow]

in my app i stopped using the application zoom level and replaced it by CSS transitions; this has several advantages:

• you can control what you want to zoom, so that e.g. interface tools remain unzoomed;
• you get smooth transitions for free which look so much better than a jumping zoom;
• plus in CSS zooming is tantamount to scaling, and 'scale' is just an intuitive factor—1 means original size, 2 means twice as big, and 0.5 is half as big.

Since i've implemented this i only use the application zoom to select an initial app zoom state so that a scale of 1 means that 1mm in the CSS approximately matches 1mm on the screen, but even for that an additional factor in the CSS might be used.

The only case where application still matters to me is the fact that font and box metrics seem to be more fractional / numerically unstable (?) at small app zoom levels (i have an open question on this problem on http://stackoverflow.com/questions/29035656/why-do-rendered-pixels-differ-from-real-pixels; maybe you people have an idea what's going on?).

+1 for app zoom support that uses a scaling factor and supports smooth zooming. Then again, you can easily implement it yourself.

[felicienfrancois]

var zoomPercent = 150;
var win = require("nw.gui").Window.get();
win.zoomLevel = Math.log(zoomPercent/100) / Math.log(1.2);

[loveencounterflow]

Does that mean that the zoom level is the logarithm to base 1.2 of the scaling factor?