Motion: Support predictive back in Container transform #102
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Change-Id: I9adb4a48be47761dc725f67e50be872a8865587a
| override fun handleOnBackPressed() { | ||
| // This invokes the sharedElementReturnTransition, which is | ||
| // MaterialContainerTransform. | ||
| // TODO: It pops the scaleX/Y back to 1f. It would look nicer to retain the |
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It's the transition after the back gesture is committed (e.g. MaterialContainerTransform for the sharedElementReturnTransition) that is popping the scale back to 1f?
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Shared elements are copied into the target fragment before the transition animations start. It seems the scale and other transformations are dropped in the process. I tried using a set of ChangeTransform (it handles scaleX/Y) and MaterialContainerTransform, but it doesn't work for some reason.
I updated the formula below, and this is hardly unnoticeable. I think I don't care about this for now.
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with the updated formulas the reset is not very noticeable at all
thanks Yuichi!
| // TODO: Consider handling backEvent.touchY to reflect the vertical movement. | ||
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| // Scale down from 100% to 50%. | ||
| val scale = (2f - progress) * 0.5f |
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the formula is 1F - (0.1F * progress) because the max scale is 90%
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Updated. I suppose you mean the "min" scale.
| override fun handleOnBackProgressed(backEvent: BackEventCompat) { | ||
| val progress = backEvent.progress | ||
| // Translate as far as 20% of finger movement. | ||
| val translation = progress * background.width * 0.2f |
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the formula for translationX is (progress * maxXShift) for the left edge and -(progress * maxXShift) for the right edge, where maxXShift is windowWidth / 20
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Thank you. I didn't know we had a motion spec.
Change-Id: I8ccbc5267ecd3aae1c1179ff5a7036030896ba8a
pb.webm |
Change-Id: I8f438fe1aa25dcd452872495dd132ed62fba030e
Change-Id: I9adb4a48be47761dc725f67e50be872a8865587a