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Custom Views and ViewGroups

Custom ViewGroups (Part 3): onMeasure Helpers

12/06/2017

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In this lesson, we will look at four methods in the `ViewGroup` class that can help simplify `onMeasure` logic when creating a base `ViewGroup` class: - `getChildMeasureSpec` for helping calculate `MeasureSpec` values for child views given the `ViewGroup`'s own `MeasureSpec` values and the `LayoutParams` of the child - `measureChild`/`measureChildren` for simply measuring children whose size and position are independent of other views, like in `FrameLayout` - `measureChildWithMargin` for measuring children while taking margins into account as well when the children's size and position depend on other views as in `LinearLayout` - How do all of the measure helpers use `getChildMeasureSpec` to do the hard work - When do we want to use each helper method

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