How do you set a mapbox map to the user's location at initialization? I understand that you can go to the user's location programmatically like this:
if (navigator.geolocation) {
navigator.geolocation.getCurrentPosition(e => {
map.jumpTo({center: [e.coords.longitude, e.coords.latitude]})
})
}
But this first initializes the map at some default location, and then goes to the user's location. I've also tried moving this call to navigator.geolocation to before the map gets initialized, but since this calls navigator.geolocation that takes a little longer and the result is still that the map loads momentarily showing the default location, then going to where the user is. Trying to get the lat and lng from navigator and then passing those to the map constructor should work, but I'm having trouble getting the map to wait for those variables without causing issues.
More importantly, this seems like a feature that would have broad appeal so I feel like I'm overcomplicating it. How do you start the map at the user's location?
Just don't create the map until you know the location.
function initMap(lngLat) {
window.map = new mapboxgl.Map({
center: lngLat,
// ...
});
// more initialization
});
if (navigator.geolocation) {
navigator.geolocation.getCurrentPosition(e => {
initMap([e.coords.longitude, e.coords.latitude])
})
} else {
initMap([ /* default location */ ]);
}
You will obviously also have to disable any other functionality that depends on the map being loaded, until that point.
Related
I'm using react-navigation v1.x. I like to have a global access to navigation prop of a navigator. My hope is that if I doglobalNavigation.addListener() or goBack etc with no arguments, it should be as if I did that from the currently focused screen. I also want to pass it some argument, so that it should be as if I called it rom a certain "key". I use this global from various places (like redux middleware etc).
Would be very useful to also get "getCurrentRouteName" and "getCurrentRouteKey". In pre v1.x I had done custom stuff in routers, and was hoping to avoid that now.
I tried to have a ref to the navigator and use ref._navigation for things like navigate, goBack, etc. I wanted to use it with addListener.
Here is how I get and hold the ref:
export AppNavigatorUtils = {}
class AppContent extends Component<Props> {
constructor(props: Props) {
super(props);
AppNavigatorUtils.getNavigation = this.getNavigation;
}
render() {
return (
<AppNavigator ref={this.refNavigator} />
)
}
refNavigator = el => this.navigator = el
getNavigation = () => this.navigator ? this.navigator._navigation : null
}
Doing AppNavigatorUtils.getNavigation().addListener('didBlur, (e) => console.log('blur from e:', e)) is not working. I expected this to add listener to the currently in focus screen.
Anyone any ideas?
I defined a new type of model element as a plug-in; let's refer to it as Foo. A Foo node in the model should translate to a section element in the view. So far, so good. I managed to do that by defining simple conversion rules. I also managed to define a new FooCommand that transforms (renames) selected blocks to Foo.
I got stuck trying to have attributes on those Foo model nodes be translated to attributes on the view elements (and vice-versa). Suppose Foos have an attribute named fooClass which should map to the view element's class attribute.
<Foo fooClass="green-foo"> should map to/from <section class="green-foo">
I can successfully receive parameters in FooCommand, but I can't seem to set them on the blocks being processed by the command:
execute(options = {}) {
const document = this.editor.document;
const fooClass = options.fooClass;
document.enqueueChanges(() => {
const batch = options.batch || document.batch();
const blocks = (options.selection || document.selection).getSelectedBlocks();
for (const block of blocks) {
if (!block.is('foo')) {
batch.rename(block, 'foo');
batch.setAttribute(block, 'fooClass', fooClass);
}
}
});
}
Below is the code for the init function in the Foo plugin, including the model→view and view→model conversions:
init() {
const editor = this.editor;
const doc = editor.document;
const data = editor.data;
const editing = editor.editing;
editor.commands.add('foo', new FooCommand(editor));
doc.schema.registerItem('foo', '$block');
buildModelConverter().for(data.modelToView, editing.modelToView)
.fromElement('foo')
.toElement(modelElement => {
const fooClass = modelElement.item.getAttribute('fooClass'));
return new ContainerElement('section', {'class': fooClass});
});
buildViewConverter().for(data.viewToModel)
.fromElement('section')
.toElement(viewElement => {
let classes = Array.from(viewElement.getClassNames());
let modelElement = new ModelElement('foo', {'fooClass': classes[0]});
return modelElement;
});
}
When I try to run the command via
editor.execute('foo', { fooClass: 'green-foo' })
I can see that the green-foo value is available to FooCommand, but the modelElement in the model→view conversion, on the other hand, has no fooClass attribute.
I'm sure I'm missing the point here and misusing the APIs. I'd be really thankful if someone could shed some light on this issue. I can provide more details, as needed.
Follow-up after initial suggestions
Thanks to #Reinmar and #jodator for their suggestion regarding configuring the document schema to allow for the custom attribute. I really thought that would have taken care of it, but no. It may have been a necessary step anyway, but I'm still unable to get the attribute value from the model element during the model→view conversion.
First, let me add an important piece of information I had left out: the CKEditor5's version I'm working with is 1.0.0-alpha2. I am aware several of the APIs are bound to change, but I would still like to get things working with the present version.
Model→view conversion
If I understand it correctly, one can either pass a string or a function to the toElement call. A question about using the latter: what exactly are the parameters passed to the function? I assumed it would be the model element (node?) to be converted. Is that the case? If so, why is the attribute set on that node via batch.setAttribute (inside a document.enqueueChanges) not available when requested? Should it be?
A sequencing problem?
Additional testing seems to indicate there's some kind of order-of-execution issue happening. I've observed that, even though the attribute is not available when I first try to read it from the modelElement parameter, it will be so if I read it again later. Let me try to illustrate the situation below. First, I'll modify the conversion code to make it use some dummy value in case the attribute value is not available when read:
buildModelConverter().for(data.modelToView, editing.modelToView)
.fromElement('foo')
.toElement(modelElement => {
let fooClass = modelElement.item.getAttribute('fooClass') || 'naught';
let viewElement = new ContainerElement('section');
viewElement.setAttribute('class', fooClass);
return viewElement;
});
Now I reload the page and execute the following instructions on the console:
c = Array.from(editor.document.getRoot().getChildren());
c[1].is('paragraph'); // true
// Changing the node from 'paragraph' to 'foo' and adding an attribute
// 'fooClass' with value 'green-foo' to it.
editor.document.enqueueChanges(() => {
const batch = editor.document.batch();
batch.rename(c[1], 'foo');
batch.setAttribute(c[1], 'fooClass', 'green-foo');
return batch;
});
c[1].is('paragraph'); // false
c[1].is('foo'); // true
c[1].hasAttribute('fooClass'); // true
c[1].getAttribute('fooClass'); // 'green-foo'
Even though it looks like the expected output is being produced, a glance at the generated view element shows the problem:
<section class="naught"/>
Lastly, even if I try to reset the fooClass attribute on the model element, the change is not reflected on the view element. Why is that? Shouldn't changes made via enqueueChanges cause the view to update?
Sorry for the very long post, but I'm trying to convey as many details as I can. Here's hoping someone will spot my mistake or misunderstanding of how the CKEditor 5's API actually works.
View not updating?
I turned to Document's events and experimented with the changesDone event. It successfully addresses the "timing" issue, as it consistently triggers only after all changes have been processed. Still, the problem of the view not updating in response to a change in the model remains. To make it clear, the model does change, but the view does not reflect that. Here is the call:
editor.document.enqueueChanges(() => editor.document.batch().setAttribute(c[1], 'fooClass', 'red-foo'));
To be 100% sure I wrote the whole feature myself. I use the 1.0.0-beta.1 API which is completely different than what you had.
Basically – it works. It isn't 100% correct yet, but I'll get to that.
How to convert an element+attribute pair?
The thing when implementing a feature which needs to convert element + attribute is that it requires handling the element and attribute conversion separately as they are treated separately by CKEditor 5.
Therefore, in the code below you'll find that I used elementToElement():
editor.conversion.elementToElement( {
model: 'foo',
view: 'section'
} );
So a converter between model's <foo> element and view's <section> element. This is a two-way converter so it handles upcasting (view -> model) and downcasting (model -> view) conversion.
NOTE: It doesn't handle the attribute.
Theoretically, as the view property you could write a callback which would read the model element's attribute and create view element with this attribute set too. But that wouldn't work because such a configuration would only make sense in case of downcasting (model -> view). How could we use that callback to downcast a view structure?
NOTE: You can write converters for downcast and upcast pipelines separately (by using editor.conversion.for()), in which case you could really use callbacks. But it doesn't really make sense in this case.
The attribute may change independently!
The other problem is that let's say you wrote an element converter which sets the attribute at the same time. Tada, you load <section class=ohmy> and gets <foo class=ohmy> in your model.
But then... what if the attribute will change in the model?
In the downcast pipeline CKEditor 5 treats element changes separately from attribute changes. It fires them as separate events. So, when your FooCommand is executed on a heading it calls writer.rename() and we get the following events in DowncastDispatcher:
remove with <heading>
insert:section
But then the attribute is changed too (writer.setAttribute()), so we also get:
setAttibute:class:section
The elementToElement() conversion helper listens to insert:section event. So it's blind to setAttribute:class:selection.
Therefore, when you change the value of the attribute, you need the attributeToAttribute() conversion.
Sequencing
I didn't want to reply to your question before we released 1.0.0-beta.1 because 1.0.0-beta.1 brought the Differ.
Before 1.0.0-beta.1 all changes were converted immediately when they were applied. So, rename() would cause immediate remove and insert:section events. At this point, the element that you got in the latter one wouldn't have the class attribute set yet.
Thanks to the Differ we're able to start the conversion once all the changes are applied (after change() block is executed). This means that the insert:section event is fired once the model <foo> element has the class attribute set already. That's why you could write a callback-based converters... bur you shouldn't :D
The code
import { downcastAttributeToAttribute } from '#ckeditor/ckeditor5-engine/src/conversion/downcast-converters';
import { upcastAttributeToAttribute } from '#ckeditor/ckeditor5-engine/src/conversion/upcast-converters';
class FooCommand extends Command {
execute( options = {} ) {
const model = this.editor.model;
const fooClass = options.class;
model.change( writer => {
const blocks = model.document.selection.getSelectedBlocks();
for ( const block of blocks ) {
if ( !block.is( 'foo' ) ) {
writer.rename( block, 'foo' );
writer.setAttribute( 'class', fooClass, block );
}
}
} );
}
}
class FooPlugin extends Plugin {
init() {
const editor = this.editor;
editor.commands.add( 'foo', new FooCommand( editor ) );
editor.model.schema.register( 'foo', {
allowAttributes: 'class',
inheritAllFrom: '$block'
} );
editor.conversion.elementToElement( {
model: 'foo',
view: 'section'
} );
editor.conversion.for( 'upcast' ).add(
upcastAttributeToAttribute( {
model: 'class',
view: 'class'
} )
);
editor.conversion.for( 'downcast' ).add(
downcastAttributeToAttribute( {
model: 'class',
view: 'class'
} )
);
// This should work but it does not due to https://github.com/ckeditor/ckeditor5-engine/issues/1379 :(((
// EDIT: The above issue is fixed and will be released in 1.0.0-beta.2.
// editor.conversion.attributeToAttribute( {
// model: {
// name: 'foo',
// key: 'class'
// },
// view: {
// name: 'section',
// key: 'class'
// }
// } );
}
}
This code works quite well, except the fact that it converts the class attribute on any possible element that has it. That's because I had to use very generic downcastAttributeToAttribute() and upcastAttributeToAttribute() converters because of a bug that I found (EDIT: it's fixed and will be available in 1.0.0-beta.2). The commented out piece of code is how you it should be defined if everything worked fine and it will work in 1.0.0-beta.2.
It's sad that we missed such a simple case, but that's mainly due to the fact that all our features... are much more complicated than this.
Collaboration Mode:
What is the best way to propagate changes from Client #1's canvas to client #2's canvas? Here's how I capture and send events to Socket.io.
$scope.canvas.on('object:modified',function(e) {
Socket.whiteboardMessage({
eventId:'object:modified',
event:e.target.toJSON()
});
});
On the receiver side, this code works splendidly for adding new objects to the screen, but I could not find documentation on how to select and update an existing object in the canvas.
fabric.util.enlivenObjects([e.event], function(objects) {
objects.forEach(function(o) {
$scope.canvas.add(o);
});
});
I did see that Objects have individual setters and one bulk setter, but I could not figure out how to select an existing object based on the event data.
Ideally, the flow would be:
Receive event with targeted object data.
Select the existing object in the canvas.
Perform bulk update.
Refresh canvas.
Hopefully someone with Fabric.JS experience can help me figure this out. Thanks!
UPDATED ANSWER - Thanks AJM!
AJM was correct in suggesting a unique ID for every newly created element. I was also able to create a new ID for all newly created drawing paths as well. Here's how it worked:
var t = new fabric.IText('Edit me...', {
left: $scope.width/2-100,
top: $scope.height/2-50
});
t.set('id',randomHash());
$scope.canvas.add(t);
I also captured newly created paths and added an id:
$scope.canvas.on('path:created',function(e) {
if (e.target.id === undefined) {
e.target.set('id',randomHash());
}
});
However, I encountered an issue where my ID was visible in console log, but it was not present after executing object.toJSON(). This is because Fabric has its own serialization method which trims down the data to a standardized list of properties. To include additional properties, I had to serialize the data for transport like so:
$scope.canvas.on('object:modified',function(e) {
Socket.whiteboardMessage({
object:e.target.toJSON(['id']) // includes "id" in output.
})
});
Now each object has a unique ID with which to perform updates. On the receiver's side of my code, I added AJM's object-lookup function. I placed this code in the "startup" section of my application so it would only run once (after Fabric.js is loaded, of course!)
fabric.Canvas.prototype.getObjectById = function (id) {
var objs = this.getObjects();
for (var i = 0, len = objs.length; i < len; i++) {
if (objs[i].id == id) {
return objs[i];
}
}
return 0;
};
Now, whenever a new socket.io message is received with whiteboard data, I am able to find it in the canvas via this line:
var obj = $scope.canvas.getObjectById(e.object.id);
Inserting and removing are easy, but for updating, this final piece of code did the trick:
obj.set(e.object); // Updates properties
$scope.canvas.renderAll(); // Redraws canvas
$scope.canvas.calcOffset(); // Updates offsets
All of this required me to handle the following events. Paths are treated as objects once they're created.
$scope.canvas.on('object:added',function(e) { });
$scope.canvas.on('object:modified',function(e) { });
$scope.canvas.on('object:moving',function(e) { });
$scope.canvas.on('object:removed',function(e) { });
$scope.canvas.on('path:created',function(e) { });
I did something similar involving a single shared canvas between multiple users and ran into this exact issue.
To solve this problem, I added unique IDs (using a javascript UUID generator) to each object added to the canvas (in my case, there could be many users working on a canvas at a time, thus I needed to avoid collisions; in your case, something simpler could work).
Fabric objects' set method will let you add an arbitrary property, like an id: o.set('id', yourid). Before you add() a new Fabric object to your canvas (and send that across the wire), tack on an ID property. Now, you'll have a unique key by which you can pick out individual objects.
From there, you'd need a method to retrieve an object by ID. Here's what I used:
fabric.Canvas.prototype.getObjectById = function (id) {
var objs = this.getObjects();
for (var i = 0, len = objs.length; i < len; i++) {
if (objs[i].id == id) {
return objs[i];
}
}
return null;
};
When you receive data from your socket, grab that object from the canvas by ID and mutate it using the appropriate set methods or copying properties wholesale (or, if getObjectById returns null, create it).
I am facing the following problem,
I have an object called "data". It has three properties, one of it being itemRendererData. The "itemRendererData" is an ArrayCollection of objects having many properties one of which is the property "imageURL" (datatype:String).
I am working in flex. I have defined the view and the item renderer properly. The view has the data. I am supposed to get the images from the url specified by imageURL property.
In the itemRenderer, I have declared, source
source = {data.itemRendererData.imageURL}
But the images are not being displayed.
Use a the FlexEvent.DATA_CHANGE handler rather than binding, which is actually the proper way to handle this and gives you far more control.
public function CustomItemRenderer() {
this.addEventListener(FlexEvent.DATA_CHANGE, this.dataChangeHandler);
this.addEventListener(FlexEvent.CREATION_COMPLETE, this.creationCompleteHandler);
}
private function creationCompleteHandler(e:FlexEvent) {
if (this.data) {
this.image.source = this.data.itemRendererData.imageURL;
}
}
private function dataChangeHandler(e:FlexEvent) {
if (this.data && this.initialized) {
this.image.source = this.data.itemRendererData.imageURL;
}
}
You will notice that I have a handler for FlexEvent.CREATION_COMPLETE as well. This is because the data is actually set before the components are created. So the first time a renderer is loaded, this.image is null and this.image.source will error out.
If that doesn't work, you also need to make sure that the Image/BitmapImage is not a direct child of the renderer. I never did figure out why this was, but adding it as a child of Group fixed that issue where the image was being set but not rendering. Again, I have no idea why this was and I tested for a few hours trying to figure it out.
As an added tip, avoid MXML-based ItemRenderers in mobile applications. They are noticeably slower than pure-AS3 renderers.
Im working on a MVVM Windows phone app that displays weather info.
When the app loads up it opens MainPage.xaml. It makes a call the the service to get weather info and binds that data to the UI. Both Fahrenheit and Celcius info are returned but only one is displayed.
On the setting page, the user can select to view the temp in either Fahrenheit or Celcius.
The user can change this setting at any time and its stored in IsolatedStorageSettings.
The issue Im having is this:
when the user navigates to the Settings page and changes their preference for either Fahrenheit or Celcius, this change is not reflected on the main page.
This issue started me thinking about this in a broader context. I can see this being an issue in ANY MVVM app where the display depends on some setting in IsolatedStorage. Any time any setting in the IsoStore is updated, how does the ViewModels know this? When I navigate back in the NavigationStack from the settings page back to MainPage how can I force a rebind of the page?
The data in my model hasnt changed, only the data that I want to display has changed.
Am I missing something simple here?
Thanks in advance.
Alex
Probably you have code like this:
public double DisplayTemperature
{
get { return (IsCelsium) ? Celsium : Fahrenheit; }
}
And IsCelsium is:
public double IsCelsium
{
get { return (bool)settings["IsCelsium"]; }
set { settings["IsCelsium"] = value; }
}
So you need to add NotifyPropertyChanged event to notify UI to get new values from DisplayTemperature property:
public double IsCelsium
{
get { return (bool)settings["IsCelsium"]; }
set
{
settings["IsCelsium"] = value;
NotifyPropertyChanged("DisplayTemperature");
}
}
Take a look at Caliburn Micro. You could implement something similar or use CM itself. When using CM I don't even think about this stuff, CM makes it so simple.
When your ViewModel inherits from Screen there are life-cycle events that fire that you can override. For example, OnInitialize fires the very first time the ViewModel is Activated and OnActivate fires every time the VM is activated. There's also OnViewAttached and OnViewLoaded.
These methods are the perfect place to put logic to populate or re-populate data.
CM also has some special built in features for allowing one to easily tombstone a single property or an entire object graph into Iso or phone state.
ok, so Ive come up with a solution. Before I get to it, let me provide some background. The app that Im working on uses both MVVM Light and WP7Contrib. That being the case, I am using Funq for DI and the MVVMLight Toolkit. After I posted my initial question, I gave the question a bit more thought. I remembered a video that I watched a while back from MIX2011 called Deep Dive MVVM with Laurent Bugnion
http://channel9.msdn.com/Events/MIX/MIX11/OPN03
In it, he talks about just this problem (view models not living at the same time) on Windows Phone. The part in question starts around the 19 minute mark.
Anyway, after I remembered that and realized that the ViewModel locator is exposed in App.xaml, this became a trivial problem to solve. When the user changes the Fahrenheit/Celcius option on the setting page, I simply get a reference to the MainViewModel via the ViewModelLocator and reset the collection that is bound to the UI thus causing the bindings to update.
public bool AddOrUpdateValue(string Key, Object value)
{
bool valueChanged = false;
// If the key exists
if (settings.Contains(Key))
{
// If the value has changed
if (settings[Key] != value)
{
// Store the new value
settings[Key] = value;
valueChanged = true;
}
}
// Otherwise create the key.
else
{
settings.Add(Key, value);
valueChanged = true;
}
return valueChanged;
}
public bool ImperialSetting
{
get
{
return GetValueOrDefault<bool>(ImperialSettingKeyName, ImperialSettingDefault);
}
set
{
if (AddOrUpdateValue(ImperialSettingKeyName, value))
{
Save();
RaisePropertyChanged("ImperialSettingText");
var vml = new ViewModelLocator();
vml.MainViewModel.Cities = (App.Current as App).Cities;
}
}
}
It was a mistake on my part not to realize that I could get access to the viewModel via the ViewModelLocator. Hopefully this post saves someone else the time I burned on this issue.