Does anyone know where one can find a description of the meaning of various "icons" and / or symbols one finds next to classes and methods in various browsers?
Some classes define icons depending on their type. Collections, Streams, Morphs, Numbers, Exceptions, Announcements, Tests, etc. Have a look at the class hierarchy to understand the icon.
For methods there are two sets of icons. The first set is related to the class hierarchy:
Up arrow: The method overrides a method in the superclass.
Down arrow: The method is overridden by a method in a subclass.
Up and down arrow: The method overrides a method in the superclass and is overridden by a method in a subclass.
The second set is used for test classes only:
Green dot: The last run of the test method was a success.
Orange dot: The last run of the test method was a failure.
Red dot: The last run of the test method was an error.
Gray dot: The test method was not recently run.
Pharo by Example describes on page 114 some of these icons in more detail. Also this website contains a slightly outdated list of icons.
If you want to understand the implementation of the different icons have a look at the following two methods: The class icons are defined in #browserIcon and the method icons in #browerIcon:selector:.
Related
Given:
#property({type: Boolean, attribute: 'some-attr'}) someAttr = false;
I was expecting to see updated being fired once 'some-attr' value gets updated in the DOM.
However, updated doesn't get fired at all.
Is my expectation wrong, or should I set things up differently?
Looking at Elm's discussion of properties vs attributes, the documentation of the Html.Attributes module's attribute function, and the Elm documentation on custom elements, I am pretty sure, that this is caused by simply binding an elm expression to attribute some-attr of the LitElement based custom element. I.e. the DOM attribute will always be present and hence the corresponding property always be true.
The default converter for Boolean (activated by providing type:Boolean to the decorator) mimicks the behaviour of HTML attributes used as flags (e.g. disabled on an <input> element): If the attribute is present (no matter the value), the flag is set (true). The implementation is really straight forward, if you want to look at it in the sources: https://github.com/Polymer/lit-element/blob/master/src/lib/updating-element.ts#L163
I see these options for your problem:
Implement some extra logic in Elm to add / remove the presence of the attribute.
Create your own attribute converter for the LitElement based custom element.
Use another default converter (e.g. for String, the "default" default converter) and implement the custom logic inside the LitElement (e.g. using a derived value).
Of these 3 options, I would generally recommend the first one, as your custom element then still behaves naturally, i.e. if some-attr should be a flag (boolean attribute), then following which HTML semantics, it should be defined by its presence, not its value. This allows you to re-use it in other projects without surprising other developers.
That being said, there may of course be project-specific requirements, that are more important. E.g. if you only use this custom element in this one project with Elm, your road to success may be faster going for options 2 or 3.
My previous company used to prefix interfaces with an I. For instance: ICar. I found that useful as the answer to whether a class was an interface or a concrete class was 0 clicks away. My current company, however, does not adopt that rule and just name the interfaces normally, without prefixing it with anything. Now if I come across this type of code:
Car car = new Tesla();
I have to go into the Car class to know if it is an interface or a class. I find that pretty annoying. Is there a way to make the IDE (in this case Android Studio/IntelliJ) to color/style those in a different way? (Much like they do with fields, i.e., fields are coloured in purple so you know you are not dealing with a local variable instead).
Go to File → Settings, then in the sidebar select Editor → Color Scheme → Language Defaults.
Expand "Classes" and you will be able to apply custom styling options to Classes and Interfaces. (I personally color class names light blue and interface names green to match their icons in IntelliJ.)
If you want to color Abstract classes and Enum classes uniquely as well, you can do so under the "Java" section, rather than "Language Defaults".
In many occasions JavaFX needs to be customized with classes that extend existing ones. I tried this approach, for example to add a method to the NumberAxis class that would enable the label of the axis to be rotated.
But I got a "NumberAxis is declared final, can't be extended" compiler error. I wonder how people who extend classes do? Do they have access to the source code of javafx, modify it to make some classes not final, and recompile it? (sounds tricky! )
Making lots of classes final in the JavaFX framework was an intentional decision by the framework developers. To get a flavor of why it's done, see the Making Color Final proposal. That's just an example, there are other reasons. I think experience with subclassing in the Swing framework was that it caused errors and maintenance issues that the JavaFX designers wanted to avoid, so many things are made final.
There are other way to extend functionality than to directly subclass. Some alternatives for your rotation example:
aggregation: include the NumberAxis as a member of new class (e.g. NumberAxisWithRotatableText) which adds an accessor to get the underlying NumberAxis node and a method to perform the rotation (e.g. via a lookup as explained below).
composition: for example extend Pane, add a NumberAxis, disable the standard text drawing on the axis and add rotated labels yourself as needed.
css stylesheet: for example use a selector to lookup the text in the NumberAxis and the -fx-rotate attribute to rotate it.
node lookup: Use a node.lookup to get at the underlying text node, and apply the rotation via an API.
skin: All controls have a skin class attached them, replace the default skin class with a custom one.
subclass an alternate class: Subclass the abstract ValueAxis class rather than the final NumberAxis class.
Source code for JavaFX is available with build instructions. However, I don't recommend hacking a personal copy of the source code to remove final constructs unless you also submit it as an accepted patch to the JavaFX system so that you can be sure that your app won't break on a standard JavaFX install.
If you really think it is a good idea for a given class to be subclassable, then log a change request. Sometimes the JavaFX developers are overzealous and make stuff final which would be better not being final. NumberAxis perhaps falls into that category.
I've a layer with multiple markers with rather big icons, so they overlap. Via the list on the side of the map users can select a marker and the map will pan (and zoom) to it. But it will still be behind some other makers.
How do I get a individual makers z-index and set it? I would be useful to get the highest used z-index and just add one. (another solution is to add the total number of markers to the z-index)
The markers (or features) are in a myLib.features array. The console doesn't show any z-index type functions.
I can't find a appropriate example or api function for this.
EDIT:
I found this example: http://dev.openlayers.org/examples/ordering.html
I don't really understand it. Somehow the created feature takes the next z-index given by the layer via somekind of symbolizer. I have no idea how to work this static sort into a dynamic one.
Try this:
First of all, make sure you are using a OpenLayers.Layer.Vector layer, not a OpenLayers.Layer.Markers layer. Apparently the Markers layer is old news and all new development is done in the Vector layer. It has more features. (I wasted a pile of time with the Markers layer myself).
Then, each of your markers needs to be a OpenLayers.Feature.Vector object. The constructor takes three arguments, the third of which is called the style. The style is where you set your image attributes, the background shadow, the mouse-over text, and the z-index, which has the property name "graphicZIndex". I think that's what you're looking for.
http://dev.openlayers.org/releases/OpenLayers-2.12/doc/apidocs/files/OpenLayers/Feature/Vector-js.html#OpenLayers.Feature.Vector.OpenLayers.Feature.Vector.style
Add your "markers" (which are Vector's) to your Vector layer with the addFeatures function. And just ignore the "options" argument.
http://dev.openlayers.org/releases/OpenLayers-2.12/doc/apidocs/files/OpenLayers/Layer/Vector-js.html#OpenLayers.Layer.Vector.addFeatures
I found that example page too, and I found it confusing too. It was setting all the markers' styles in the Vector layer's constructor (as default values to be used if the marker style was omitted) instead of the marker's constructor. I think it makes more sense to set the marker style in the marker constructor.
To change the style in real-time, take one of your OpenLayers.Feature.Vector markers, called "marker" and do this. And let's call the Vector Layer "layer".
marker.style.graphicZIndex = 13;
layer.redraw();
I'm just using StarUML to create my UML Class diagram and something is bothering me. I create an interface representation, which is a circle, however, there is no room to add which methods and attributes the interface defines. Is this normal UML practice?
If not, how do you know (say a class implements this interface and has 4 methods defined) which of the 4 methods came from the interface and which didnt?
Solved:
Ok just incase someone else has this problem- there are two notations, both are possible in StarUML but only one explicitly (the dot notation). To create the <> notation, enter the name as <> IInterface_Name and then draw a realisation line between the implementing classes. Be sure to manually delete the old (wrong) relationship you had by right clicking the class, collection editor and then relations.
It is very simple:
If you need just show method of interface - right click on interface and un-select Format/Suppress operation (see blue circle on picture)
If you need to display instead of circle just squared form of interface (on my picture it is ISome) use Format/Stereotype Display/Decoration (see red circle on picture bellow)