A standard format for representing motion specifications in Objective-C and Swift.
CocoaPods is a dependency manager for Objective-C and Swift libraries. CocoaPods automates the process of using third-party libraries in your projects. See the Getting Started guide for more information. You can install it with the following command:
gem install cocoapods
Add MotionInterchange
to your Podfile
:
pod 'MotionInterchange'
Then run the following command:
pod install
Import the framework:
@import MotionInterchange;
You will now have access to all of the APIs.
Check out a local copy of the repo to access the Catalog application by running the following commands:
git clone https://github.com/material-motion/motion-interchange-objc.git
cd motion-interchange-objc
pod install
open MotionInterchange.xcworkspace
- Architecture
- How to define a cubic bezier animation
- How to define a spring animation
- How to define a motion spec
This library defines a format for representing motion in Objective-C and Swift applications. The
primary data type, MotionTiming
, allows you to describe the duration, delay, timing curve, and
repetition for an animation.
In Objective-C:
MDMMotionTiming timing = (MDMMotionTiming){
.delay = 0.150,
.duration = 0.225,
.curve = _MDMBezier(0.4f, 0.0f, 0.2f, 1.0f)
}
In Objective-C:
MDMMotionTiming timing = (MDMMotionTiming){
.curve = _MDMSpring(1, 100, 10)
}
Motion timing structs can be used to represent complex multi-element and multi-property motion specifications. An example of a common complex motion spec is a transition which has both an expansion and a collapse variant. If we wanted to represent such a transition we might create a set of structures like this:
struct MDCMaskedTransitionMotionTiming {
MDMMotionTiming contentFade;
MDMMotionTiming floodBackgroundColor;
MDMMotionTiming maskTransformation;
MDMMotionTiming horizontalMovement;
MDMMotionTiming verticalMovement;
MDMMotionTiming scrimFade;
};
typedef struct MDCMaskedTransitionMotionTiming MDCMaskedTransitionMotionTiming;
struct MDCMaskedTransitionMotionSpec {
MDCMaskedTransitionMotionTiming expansion;
MDCMaskedTransitionMotionTiming collapse;
BOOL shouldSlideWhenCollapsed;
BOOL isCentered;
};
typedef struct MDCMaskedTransitionMotionSpec MDCMaskedTransitionMotionSpec;
We can then implement a spec like so:
#define MDMEightyForty _MDMBezier(0.4f, 0.0f, 0.2f, 1.0f)
#define MDMFortyOut _MDMBezier(0.4f, 0.0f, 1.0f, 1.0f)
struct MDCMaskedTransitionMotionSpec fullscreen = {
.expansion = {
.contentFade = {
.delay = 0.150, .duration = 0.225, .curve = MDMEightyForty,
},
.floodBackgroundColor = {
.delay = 0.000, .duration = 0.075, .curve = MDMEightyForty,
},
.maskTransformation = {
.delay = 0.000, .duration = 0.105, .curve = MDMFortyOut,
},
.horizontalMovement = {.curve = { .type = MDMMotionCurveTypeInstant }},
.verticalMovement = {
.delay = 0.045, .duration = 0.330, .curve = MDMEightyForty,
},
.scrimFade = {
.delay = 0.000, .duration = 0.150, .curve = MDMEightyForty,
}
},
.shouldSlideWhenCollapsed = true,
.isCentered = false
};
We can then use this motion spec to implement our animations in a transition like so:
MDCMaskedTransitionMotionTiming timing = isExpanding ? fullscreen.expansion : fullscreen.collapse;
// Can now use timing's properties to associate animations with views.
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Licensed under the Apache 2.0 license. See LICENSE for details.