• Home
  • About
  • Resume

Posts tagged: effectlayer

EffectLayers gets (long overdue) remove function

By , 07/09/2015 4:50 PM

EffectLayer for Pebble Smartwatch is a library that allows you to easily add special effects to your watchfaces or watch apps. You can even add multiple effects (up to 4 by default) to a single layer. But up until now you couldn’t easily remove added effect.

This feature could be useful when you need to add/remove an effect on the fly. For example user can choose to turn off or on color inversion from watchface config, so instead of creating/showing/destroying/hiding entire layer you can simple add/remove inversion effect.

Another use case is where you need to swap effects, for example remove 90-degree rotation clockwise and add 90-degree rotation counter-clockwise.

Well now you can, the library now has effect_layer_remove_effect function. What it does is simple removes last added effect. The effect showing in the demo above is achieved by this block of code:

switch (anim_count) {
   case 0:
      effect_layer_add_effect(effect_layer, effect_invert, NULL);
      break;
   case 1:
      effect_layer_remove_effect(effect_layer);
      effect_layer_add_effect(effect_layer, effect_rotate_90_degrees, (void *)true);
      break;
   case 2:
      effect_layer_remove_effect(effect_layer);
      effect_layer_add_effect(effect_layer, effect_mirror_vertical, NULL);
      break;
   case 3:
      effect_layer_remove_effect(effect_layer);
      break;
}
  
anim_count++;
if (anim_count == 4)  anim_count = 0;

It is called every time animation movement is initiated for the layer. Layer is moved 4 times in this demo:

  • On 1st call – inversion effect is added to the layer
  • On 2nd call – last added effect (inversion) is removed and 90-degree rotation added
  • On 3rd call – 90-degree rotation removed and vertical mirror effect is added
  • On 4th call – effect is removed so now layer has no effects.

Combined the chain produced the effect shown in the animation above.

Ideally library should have “insert” and “remove_at” function to be able to insert and remove effects from arbitrary index (and not only the end of effect chain). Stay tuned.

Useful Links

Panorama Theme by Themocracy