ComBatVision
commented
5 years ago There are four solutions of this issue in JS: 1) We can declare undefined attribute selectLevelOfDetails in Placemark, expecting that somebody will assign a function with parameters dc, placemark and distance to it in application. Than call function this.selectLevelOfDetails inside determineActiveAttributes if it is defined. This approach is more suitable for JS. 2) We can declare undefined attribute levelOfDetailsSelector in Placemark, expecting that somebody will assign any object, which must have selectLevelOfDetails function with parameters dc, placemark and distance in it. Than call function this.levelOfDetailsSelector.selectLevelOfDetails if it is defined. This approach will be similar with Java and Android Interface approach, but little bit confused in JS. 3) We can combine approach 1 and 2 by impementing a setter for levelOfDetailsSelector and determine if we put function or object in it. If it is an object than just assign it to attribute, if it is a function, than wrap it into generic object. Then work with attribute as described in approach2. 4) We can define empty function selectLevelOfDetails with required parameters inside Placemark and expect that application will redefine a function in placemark or override it in possible child object implementation.
Which approach will you approve?
emxsys
WorldWindJS implementation of Placemark is missing level of details selection for placemark image source, depending on camera distance, as it was already done in Java and Android implementations.
Function makeOrderedRenderable in Placemark should execute some selectLod(dc, this, this.eyeDistance) function before this.determineActiveAttributes(dc) to allow application to define placemark attributes selection depending on this.eyeDistance.
You can look at example in Android repository.