9f5bdd7b49
Summary: Overview - This PR resolves the issue described in #14606. This PR makes Text components take into account the includeFontPadding property when calculating their size. Background - Currently, on Android, when includeFontPadding is set to false, the React Text component does not adjust its height. This makes it difficult to lay out other components at a precise spacing relative to a Text component. iOS calculates the height of a UILabel based on the font's descent + ascent. Android lets you choose whether to calculate the height of a TextView based on the font's top + bottom (includeFontPadding=true) or ascent + descent (includeFontPadding=false). In order for a text component to be the same size on iOS and Android (relative to the rest of the layout in points and dips), one should set includeFontPadding=false on Android - but the React Text component needs to take this property into account when sizing itself for this to work. Please see this stack overflow post for a visual explanation of the difference between a font's ascent/descent and top/bottom - https://stackoverflow.com/questions/27631736/meaning-of-top-ascent-baseline-descent-bottom-and-leading-in-androids-font Testing - Please see the attached screenshots to see the height difference of a Text component with this PR when includeFontPadding is true vs false. The font I am using has an ascent + descent = em-size so that the height of the Text component will be equal to the font-size for a single line of text. This is to clearly show the additional height that includeFontPadding=true adds to the Text component. For Text components that are styled in the same way, When includeFontPadding=true, height = ~29.714 dips When includeFontPadding=false, height= 24 dips <img width="342" alt="includefontpaddingtrue" src="https://user-images.githubusercontent.com/1437344/27299391-3eec9de0-54fa-11e7-81d5-d0aeb40e8e27.png"> <img width="346" alt="includefontpaddingfalse" src="https://user-images.githubusercontent.com/1437344/27299401-45c95248-54fa-11e7-98d7-17dd152d3cb8.png"> Closes https://github.com/facebook/react-native/pull/14609 Reviewed By: AaaChiuuu Differential Revision: D5587602 Pulled By: achen1 fbshipit-source-id: 6d2f12ba72ec7462676645519cd27820279278eb
React Native · 
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