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- // Copyright 2022 The Chromium Authors. All rights reserved.
- // Use of this source code is governed by a BSD-style license that can be
- // found in the LICENSE file.
- #ifndef ASH_AMBIENT_UI_AMBIENT_ANIMATION_RESIZER_H_
- #define ASH_AMBIENT_UI_AMBIENT_ANIMATION_RESIZER_H_
- #include "ash/ash_export.h"
- namespace views {
- class AnimatedImageView;
- } // namespace views
- namespace ash {
- // Each Skottie animation has fixed dimensions baked into its corresponding
- // Lottie file that were picked by UX when the animation was designed. On the
- // other hand, the UI view rendering the animation can have arbitrary
- // dimensions. AmbientAnimationResizer modifies an AnimatedImageView such that
- // its underlying Skottie animation fills its bounds according to the following
- // UX requirements:
- //
- // Let's say the view is landscape with dimensions 1000x600 and the
- // corresponding Lottie animation has dimensions 2000x1500. The animation
- // must first be scaled down to match the UI's width. Then, the animation's
- // height must be center-aligned and cropped:
- // Width scale factor = 1000 / 2000 = 0.5
- // New Animation width = 2000 * 0.5 = 1000
- // New Animation height uncropped = 1500 * 0.5 = 750
- // At this point, 750 > 600, so 150 pixels must be cropped from the height.
- // Since the animation should be center-aligned vertically, 75 pixels will be
- // cropped from the top and 75 pixels will be cropped from the bottom.
- //
- // UX has intentionally designed the ambient animations such that the above
- // case is the most common. That is to say: the animation's dimensions are
- // already larger than most views' expected dimensions, and the animation's
- // width:height aspect ratio is intentionally smaller than most if not all of
- // the expected UI aspect ratios (meaning the height gets cropped).
- //
- // Corner cases:
- // 1) If the animation's new uncropped height is *less* than the the view's
- // height, keep the new height as is and vertically center-align the
- // animation within the view's bounds.
- // 2) If the UI's width is greater than the animation's width, run the exact
- // same logic (scale the width, then crop the height). The only difference is
- // the animation will be scaled "up" instead of "down".
- class ASH_EXPORT AmbientAnimationResizer {
- public:
- // Resizes the |animated_image_view| according to the UX requirements
- // described above. The |animated_image_view| must:
- // * Have initialized non-empty bounds.
- // * Have been initialized already with a lottie::Animation.
- //
- // |padding_for_jitter| specifies the additional padding in pixels that will
- // be applied to all 4 sides of the animation when it gets resized. For
- // landscape for example, the new animation width will end up being
- // |2 * padding_for_jitter| larger than the view's width. This allows the
- // animation to be translated in any direction by the padding amount while
- // still overlapping with the view's content bounds.
- static void Resize(views::AnimatedImageView& animated_image_view,
- int padding_for_jitter = 0);
- };
- } // namespace ash
- #endif // ASH_AMBIENT_UI_AMBIENT_ANIMATION_RESIZER_H_
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