Initial Commit

lottie/objects/composition.py

@@ -0,0 +1,80 @@
+from .base import LottieObject, Index, LottieProp
+from .layers import Layer
+
+
+## @ingroup Lottie
+class Composition(LottieObject):
+    """!
+    Base class for layer holders
+    """
+    _props = [
+        LottieProp("layers", "layers", Layer, True),
+    ]
+
+    def __init__(self):
+        ## List of Composition Layers
+        self.layers = [] # ShapeLayer, SolidLayer, CompLayer, ImageLayer, NullLayer, TextLayer
+
+        self._index_gen = Index()
+
+    def layer(self, index):
+        for layer in self.layers:
+            if layer.index == index:
+                return layer
+        raise IndexError("No layer %s" % index)
+
+    def add_layer(self, layer: Layer):
+        """!
+        @brief Appends a layer to the composition
+        @see insert_layer
+        """
+        return self.insert_layer(len(self.layers), layer)
+
+    @classmethod
+    def load(cls, lottiedict):
+        obj = super().load(lottiedict)
+        obj._fixup()
+        return obj
+
+    def _fixup(self):
+        for layer in self.layers:
+            layer.composition = self
+
+    def insert_layer(self, index, layer: Layer):
+        """!
+        @brief Inserts a layer to the composition
+        @note Layers added first will be rendered on top of later layers
+        """
+        self.layers.insert(index, layer)
+        self.prepare_layer(layer)
+        return layer
+
+    def prepare_layer(self, layer: Layer):
+        layer.composition = self
+        if layer.index is None:
+            layer.index = next(self._index_gen)
+        self._on_prepare_layer(layer)
+
+    def _on_prepare_layer(self, layer):
+        raise NotImplementedError
+
+    def clone(self):
+        c = super().clone()
+        c._index_gen._i = self._index_gen._i
+        return c
+
+    def remove_layer(self, layer: Layer):
+        """!
+        @brief Removes a layer (and all of its children) from this composition
+        @param layer    Layer to be removed
+        """
+        if layer.composition is not self:
+            return
+
+        children = list(layer.children)
+
+        layer.composition = None
+        self.layers.remove(layer)
+
+        for c in children:
+            self.remove_layer(c)