I am using React Leaflet to create a custom map.
The card (Image Overlay) is currently being rendered, but it does not fill the container in which the card is placed.
The size of the container is set strictly and I would like the map to fill the container as much as possible. All attempts to resize with CSS failed.
Live example: https://codesandbox.io/s/dark-worker-8qbzfr
My code:
import "./styles.css";
import { MapContainer, ImageOverlay } from "react-leaflet";
import "leaflet/dist/leaflet.css";
const M = ({ width, height, zoom, center }) => {
const wh = [width, 500];
const origin = [0, 0];
const bounds = [origin, wh];
return (
<div style={{ width: "1100px", height: "600px" }}>
<MapContainer
style={{ height: "100%", minHeight: "100%" }}
bounds={zoom ? undefined : bounds}
boundsOptions={{
padding: [0, 0]
}}
maxBounds={bounds}
zoom={center ? zoom : undefined}
center={zoom ? center : undefined}
>
<ImageOverlay
url="../ptichnikDraw.png"
bounds={bounds}
className="map_main"
/>
</MapContainer>
</div>
);
};
const App = () => {
return (
<div
style={{
display: "flex",
justifyContent: "center"
}}
>
<M width={1500} height={500} center={[0, 0]} />
</div>
);
};
export default App;
You want your "card" (the <ImageOverlay>) to fill the initial map container/viewport.
You will not be able to do so using (only) CSS, but with Leaflet map options and methods, which are exposed by React Leaflet wrapper:
Use the Leaflet map whenReady option (exposed as a prop of <MapContainer>) to attach a callback that is executed once the map is initialized
Runs the given function fn when the map gets initialized
While not explicitly documented, that callback receives a load event argument, which target property is the newly instantiated Leaflet map
Fired when the map is initialized
Call the fitBounds() map method on that instance, with the same bounds as your Image Overlay, to have the map view be adjusted accordingly
Sets a map view that contains the given geographical bounds with the maximum zoom level possible.
Important: make sure to set the map zoomSnap option to value 0, otherwise the fitBounds will be modified so that the final zoom is a multiple of zoomSnap (default to 1, i.e. integer zoom levels)
Forces the map's zoom level to always be a multiple of this, particularly right after a fitBounds() or a pinch-zoom. By default, the zoom level snaps to the nearest integer; lower values (e.g. 0.5 or 0.1) allow for greater granularity. A value of 0 means the zoom level will not be snapped after fitBounds or a pinch-zoom.
const M = ({ width, height, zoom, center }) => {
const wh = [width, 500];
const origin = [0, 0];
const bounds = [origin, wh];
return (
<div style={{ width: "1100px", height: "600px" }}>
<MapContainer
style={{ height: "100%", minHeight: "100%" }}
bounds={zoom ? undefined : bounds}
boundsOptions={{
padding: [0, 0]
}}
maxBounds={bounds}
zoom={center ? zoom : undefined}
center={zoom ? center : undefined}
zoomSnap={0} // Important to disable snap after fitBounds
whenReady={(e) => e.target.fitBounds(bounds)} // Have the map adjust its view to the same bounds as the Image Overlay
>
<ImageOverlay
url="../ptichnikDraw.png"
bounds={bounds}
className="map_main"
/>
</MapContainer>
</div>
);
};
Updated CodeSandbox: https://codesandbox.io/s/pedantic-tree-lz1o9q
Using the default Leaflet JavaScript library you can use map.invalidateSize(). Don't know how that would work in React but maybe you can figure that one out using the documentation.
I have a View in react-native with a few components. While everything shows up correctly on the iPhone 6 and 5, when viewing it on an iPhone 4s, the bottom of one of the components is slightly cut off.
I see there are ways to scale base64 icons. Is there any way to scale an entire container View to be uniformly smaller or larger?
Your question can be break down into two parts:
1, To scale width, height, paddings and margins. These can be easily achieve by using % and aspectRatio.
2, To scale Text, you might want to consider using Extended StyleSheet, which allows you to use rem.
You can simply following tutorial "7 Tips to Develop React Native UIs For All Screen Sizes" for how to use the above tips.
Additionally, check out Extended StyleSheet Scaling, which allows to use $scale variable to scale base on conditions.
Does something like this help you ?
YourStyleSheet.js
import {StyleSheet} from 'react-native';
var Dimensions = require('Dimensions');
var {width, height} = Dimensions.get('window');
export function create(styles: Object): {[name: string]: number} {
const platformStyles = {};
Object.keys(styles).forEach((name) => {
let {sm,md,lg, ...style} = {...styles[name]};
// iphone 4s and older
if(sm && width < 375){
style = {...style, ...sm};
}
// iphone 5,5s
if(md && width >= 375 && width <414){
style = {...style, ...md};
}
// iphone 6 and bigger
if(lg && width >= 414){
style = {...style, ...lg};
}
platformStyles[name] = style;
});
return StyleSheet.create(platformStyles);
}
Then in your style you can specify the size of the component on different screen sizes like this
import YourStyleSheet from './path/YourStyleShett'
const styles = YourStyleSheet.create({
component:{
sm:{fontSize: 20,},
md:{fontSize: 30,},
lg:{fontSize: 30,},
textAlign: 'center',
marginBottom: 10,
fontWeight:'bold',
color:colors.white,
}
});
I've seen this hack for native apps to auto scroll the window, but wondering best way to do it in React Native... When a <TextInput> field gets focus and is positioned low in the view, the keyboard will cover up the text field.
You can see this issue in example UIExplorer's TextInputExample.js view.
Does anyone have a good solution?
2017 Answer
The KeyboardAvoidingView is probably the best way to go now. Check out the docs here. It is really simple compared to Keyboard module which gives Developer more control to perform animations. Spencer Carli demonstrated all the possible ways on his medium blog.
2015 Answer
The correct way to do this in react-native does not require external libraries, takes advantage of native code, and includes animations.
First define a function that will handle the onFocus event for each TextInput (or any other component you would like to scroll to):
// Scroll a component into view. Just pass the component ref string.
inputFocused (refName) {
setTimeout(() => {
let scrollResponder = this.refs.scrollView.getScrollResponder();
scrollResponder.scrollResponderScrollNativeHandleToKeyboard(
React.findNodeHandle(this.refs[refName]),
110, //additionalOffset
true
);
}, 50);
}
Then, in your render function:
render () {
return (
<ScrollView ref='scrollView'>
<TextInput ref='username'
onFocus={this.inputFocused.bind(this, 'username')}
</ScrollView>
)
}
This uses the RCTDeviceEventEmitter for keyboard events and sizing, measures the position of the component using RCTUIManager.measureLayout, and calculates the exact scroll movement required in scrollResponderInputMeasureAndScrollToKeyboard.
You may want to play around with the additionalOffset parameter, to fit the needs of your specific UI design.
Facebook open sourced KeyboardAvoidingView in react native 0.29 to solve this problem. Documentation and usage example can be found here.
We combined some of the code form react-native-keyboard-spacer and the code from #Sherlock to create a KeyboardHandler component that can be wrapped around any View with TextInput elements. Works like a charm! :-)
/**
* Handle resizing enclosed View and scrolling to input
* Usage:
* <KeyboardHandler ref='kh' offset={50}>
* <View>
* ...
* <TextInput ref='username'
* onFocus={()=>this.refs.kh.inputFocused(this,'username')}/>
* ...
* </View>
* </KeyboardHandler>
*
* offset is optional and defaults to 34
* Any other specified props will be passed on to ScrollView
*/
'use strict';
var React=require('react-native');
var {
ScrollView,
View,
DeviceEventEmitter,
}=React;
var myprops={
offset:34,
}
var KeyboardHandler=React.createClass({
propTypes:{
offset: React.PropTypes.number,
},
getDefaultProps(){
return myprops;
},
getInitialState(){
DeviceEventEmitter.addListener('keyboardDidShow',(frames)=>{
if (!frames.endCoordinates) return;
this.setState({keyboardSpace: frames.endCoordinates.height});
});
DeviceEventEmitter.addListener('keyboardWillHide',(frames)=>{
this.setState({keyboardSpace:0});
});
this.scrollviewProps={
automaticallyAdjustContentInsets:true,
scrollEventThrottle:200,
};
// pass on any props we don't own to ScrollView
Object.keys(this.props).filter((n)=>{return n!='children'})
.forEach((e)=>{if(!myprops[e])this.scrollviewProps[e]=this.props[e]});
return {
keyboardSpace:0,
};
},
render(){
return (
<ScrollView ref='scrollView' {...this.scrollviewProps}>
{this.props.children}
<View style={{height:this.state.keyboardSpace}}></View>
</ScrollView>
);
},
inputFocused(_this,refName){
setTimeout(()=>{
let scrollResponder=this.refs.scrollView.getScrollResponder();
scrollResponder.scrollResponderScrollNativeHandleToKeyboard(
React.findNodeHandle(_this.refs[refName]),
this.props.offset, //additionalOffset
true
);
}, 50);
}
}) // KeyboardHandler
module.exports=KeyboardHandler;
First you need to install react-native-keyboardevents.
In XCode, in the project navigator, right click Libraries ➜ Add
Files to [your project's name] Go to node_modules ➜
react-native-keyboardevents and add the .xcodeproj file
In XCode, in the
project navigator, select your project. Add the lib*.a from the keyboardevents
project to your project's Build Phases ➜ Link Binary With Libraries Click
.xcodeproj file you added before in the project navigator and go the Build
Settings tab. Make sure 'All' is toggled on (instead of 'Basic').
Look for Header Search Paths and make sure it contains both
$(SRCROOT)/../react-native/React and $(SRCROOT)/../../React - mark
both as recursive.
Run your project (Cmd+R)
Then back in javascript land:
You need to import the react-native-keyboardevents.
var KeyboardEvents = require('react-native-keyboardevents');
var KeyboardEventEmitter = KeyboardEvents.Emitter;
Then in your view, add some state for the keyboard space and update from listening to the keyboard events.
getInitialState: function() {
KeyboardEventEmitter.on(KeyboardEvents.KeyboardDidShowEvent, (frames) => {
this.setState({keyboardSpace: frames.end.height});
});
KeyboardEventEmitter.on(KeyboardEvents.KeyboardWillHideEvent, (frames) => {
this.setState({keyboardSpace: 0});
});
return {
keyboardSpace: 0,
};
},
Finally, add a spacer to your render function beneath everything so when it increases size it bumps your stuff up.
<View style={{height: this.state.keyboardSpace}}></View>
It is also possible to use the animation api, but for simplicity's sake we just adjust after the animation.
react-native-keyboard-aware-scroll-view solved the problem for me.
react-native-keyboard-aware-scroll-view on GitHub
Try this:
import React, {
DeviceEventEmitter,
Dimensions
} from 'react-native';
...
getInitialState: function() {
return {
visibleHeight: Dimensions.get('window').height
}
},
...
componentDidMount: function() {
let self = this;
DeviceEventEmitter.addListener('keyboardWillShow', function(e: Event) {
self.keyboardWillShow(e);
});
DeviceEventEmitter.addListener('keyboardWillHide', function(e: Event) {
self.keyboardWillHide(e);
});
}
...
keyboardWillShow (e) {
let newSize = Dimensions.get('window').height - e.endCoordinates.height;
this.setState({visibleHeight: newSize});
},
keyboardWillHide (e) {
this.setState({visibleHeight: Dimensions.get('window').height});
},
...
render: function() {
return (<View style={{height: this.state.visibleHeight}}>your view code here...</View>);
}
...
It worked for me. The view basically shrinks when the keyboard is displayed, and grows back again when its hidden.
Just wanted to mention, now there is a KeyboardAvoidingView in RN. Just import it and use it as any other module in RN.
Here is the link to the commit on RN:
https://github.com/facebook/react-native/commit/8b78846a9501ef9c5ce9d1e18ee104bfae76af2e
It is available from 0.29.0
They have also included an example on UIExplorer.
Maybe is to late, but the best solution is to use a native library, IQKeyboardManager
Just drag and drop IQKeyboardManager directory from demo project to your iOS project. That's it. Also you can setup some valus, as isToolbar enabled, or the space between text input and keyboard in the AppDelegate.m file. More details about customisation are in the GitHub page link that I've added.
I used TextInput.onFocus and ScrollView.scrollTo.
...
<ScrollView ref="scrollView">
...
<TextInput onFocus={this.scrolldown}>
...
scrolldown: function(){
this.refs.scrollView.scrollTo(width*2/3);
},
#Stephen
If you don't mind not having the height animate at exactly the same rate that the keyboard appears, you can just use LayoutAnimation, so that at least the height doesn't jump into place. e.g.
import LayoutAnimation from react-native and add the following methods to your component.
getInitialState: function() {
return {keyboardSpace: 0};
},
updateKeyboardSpace: function(frames) {
LayoutAnimation.configureNext(animations.layout.spring);
this.setState({keyboardSpace: frames.end.height});
},
resetKeyboardSpace: function() {
LayoutAnimation.configureNext(animations.layout.spring);
this.setState({keyboardSpace: 0});
},
componentDidMount: function() {
KeyboardEventEmitter.on(KeyboardEvents.KeyboardDidShowEvent, this.updateKeyboardSpace);
KeyboardEventEmitter.on(KeyboardEvents.KeyboardWillHideEvent, this.resetKeyboardSpace);
},
componentWillUnmount: function() {
KeyboardEventEmitter.off(KeyboardEvents.KeyboardDidShowEvent, this.updateKeyboardSpace);
KeyboardEventEmitter.off(KeyboardEvents.KeyboardWillHideEvent, this.resetKeyboardSpace);
},
Some example animations are (I'm using the spring one above):
var animations = {
layout: {
spring: {
duration: 400,
create: {
duration: 300,
type: LayoutAnimation.Types.easeInEaseOut,
property: LayoutAnimation.Properties.opacity,
},
update: {
type: LayoutAnimation.Types.spring,
springDamping: 400,
},
},
easeInEaseOut: {
duration: 400,
create: {
type: LayoutAnimation.Types.easeInEaseOut,
property: LayoutAnimation.Properties.scaleXY,
},
update: {
type: LayoutAnimation.Types.easeInEaseOut,
},
},
},
};
UPDATE:
See #sherlock's answer below, as of react-native 0.11 the keyboard resizing can be solved using built in functionality.
You can combine a few of the methods into something a little simpler.
Attach a onFocus listener on your inputs
<TextInput ref="password" secureTextEntry={true}
onFocus={this.scrolldown.bind(this,'password')}
/>
Our scroll down method looks something like :
scrolldown(ref) {
const self = this;
this.refs[ref].measure((ox, oy, width, height, px, py) => {
self.refs.scrollView.scrollTo({y: oy - 200});
});
}
This tells our scroll view (remember to add a ref) to scroll to down to the position of our focused input - 200 (it's roughly the size of the keyboard)
componentWillMount() {
this.keyboardDidHideListener = Keyboard.addListener(
'keyboardWillHide',
this.keyboardDidHide.bind(this)
)
}
componentWillUnmount() {
this.keyboardDidHideListener.remove()
}
keyboardDidHide(e) {
this.refs.scrollView.scrollTo({y: 0});
}
Here we reset our scroll view back to the top,
I'm using a simpler method, but it's not animated yet. I have a component state called "bumpedUp" which I default to 0, but set to 1 when the textInput gets focus, like this:
On my textInput:
onFocus={() => this.setState({bumpedUp: 1})}
onEndEditing={() => this.setState({bumpedUp: 0})}
I also have style that gives the wrapping container of everything on that screen a bottom margin and negative top margin, like this:
mythingscontainer: {
flex: 1,
justifyContent: "center",
alignItems: "center",
flexDirection: "column",
},
bumpedcontainer: {
marginBottom: 210,
marginTop: -210,
},
And then on the wrapping container, I set the styles like this:
<View style={[styles.mythingscontainer, this.state.bumpedUp && styles.bumpedcontainer]}>
So, when the "bumpedUp" state gets set to 1, the bumpedcontainer style kicks in and moves the content up.
Kinda hacky and the margins are hardcoded, but it works :)
I use brysgo answer to raise the bottom of my scrollview. Then I use the onScroll to update the current position of the scrollview. I then found this React Native: Getting the position of an element to get the position of the textinput. I then do some simple math to figure out if the input is in the current view. Then I use scrollTo to move the minimum amount plus a margin. It's pretty smooth. Heres the code for the scrolling portion:
focusOn: function(target) {
return () => {
var handle = React.findNodeHandle(this.refs[target]);
UIManager.measureLayoutRelativeToParent( handle,
(e) => {console.error(e)},
(x,y,w,h) => {
var offs = this.scrollPosition + 250;
var subHeaderHeight = (Sizes.width > 320) ? Sizes.height * 0.067 : Sizes.height * 0.077;
var headerHeight = Sizes.height / 9;
var largeSpace = (Sizes.height - (subHeaderHeight + headerHeight));
var shortSpace = largeSpace - this.keyboardOffset;
if(y+h >= this.scrollPosition + shortSpace) {
this.refs.sv.scrollTo(y+h - shortSpace + 20);
}
if(y < this.scrollPosition) this.refs.sv.scrollTo(this.scrollPosition - (this.scrollPosition-y) - 20 );
}
);
};
},
I also meet this question. Finally, I resolve it by defining the height of each scene, such as:
<Navigator
...
sceneStyle={{height: **}}
/>
And, I also use a third-party module https://github.com/jaysoo/react-native-extra-dimensions-android to get the real height.