[librsvg: 6/15] Rename snapshot_element -> render_layer

[Federico Mena Quintero <federico src gnome org>]

commit 6db7636cfd4778e479f62fdd4e30257bf43808f5
Author: Federico Mena Quintero <federico gnome org>
Date:   Mon Jul 29 11:16:22 2019 -0500

    Rename snapshot_element -> render_layer
    
    Some bug reports already use the term "layer" for the effect of
    calling render_cairo_sub() - that is, rendering an element subtree
    with its transformation within the SVG document.  So, use that
    terminology instead of "snapshot".

 librsvg_crate/src/lib.rs     | 12 ++++++------
 librsvg_crate/tests/api.rs   |  6 +++---
 rsvg_internals/src/handle.rs |  6 +++---
 3 files changed, 12 insertions(+), 12 deletions(-)
---
diff --git a/librsvg_crate/src/lib.rs b/librsvg_crate/src/lib.rs
index dae6eb4d..f04c65ab 100644
--- a/librsvg_crate/src/lib.rs
+++ b/librsvg_crate/src/lib.rs
@@ -427,10 +427,10 @@ impl<'a> CairoRenderer<'a> {
 
     /// Renders a single SVG element in the same place as for a whole SVG document
     ///
-    /// This is equivalent to `render_document`, but renders only a single
-    /// element and its children.  The element is rendered with the same
-    /// transformation matrix as it has within the whole SVG document.
-    /// Applications can use this to re-render a single element and repaint it
+    /// This is equivalent to `render_document`, but renders only a single element and its
+    /// children, as if they composed an individual layer in the SVG.  The element is
+    /// rendered with the same transformation matrix as it has within the whole SVG
+    /// document.  Applications can use this to re-render a single element and repaint it
     /// on top of a previously-rendered document, for example.
     ///
     /// Note that the `id` must be a plain fragment identifier like `#foo`, with
@@ -444,7 +444,7 @@ impl<'a> CairoRenderer<'a> {
     /// The `cr` must be in a `cairo::Status::Success` state, or this function
     /// will not render anything, and instead will return
     /// `RenderingError::Cairo` with the `cr`'s current error state.
-    pub fn snapshot_element(
+    pub fn render_layer(
         &self,
         cr: &cairo::Context,
         id: Option<&str>,
@@ -452,7 +452,7 @@ impl<'a> CairoRenderer<'a> {
     ) -> Result<(), RenderingError> {
         self.handle
             .0
-            .snapshot_element(cr, id, viewport, self.dpi, false)
+            .render_layer(cr, id, viewport, self.dpi, false)
     }
 
     /// Renders a single SVG element to a given viewport
diff --git a/librsvg_crate/tests/api.rs b/librsvg_crate/tests/api.rs
index 02ddc8da..551bb5eb 100644
--- a/librsvg_crate/tests/api.rs
+++ b/librsvg_crate/tests/api.rs
@@ -42,7 +42,7 @@ fn has_element_with_id_works() {
 }
 
 #[test]
-fn snapshot_element() {
+fn render_layer() {
     let svg = load_svg(
         br##"<?xml version="1.0" encoding="UTF-8"?>
 <svg xmlns="http://www.w3.org/2000/svg"; width="100" height="100">
@@ -65,7 +65,7 @@ fn snapshot_element() {
             height: 100.0,
         };
 
-        renderer.snapshot_element(&cr, Some("#bar"), &viewport)
+        renderer.render_layer(&cr, Some("#bar"), &viewport)
     };
 
     let output_surf = res
@@ -86,7 +86,7 @@ fn snapshot_element() {
 
     let reference_surf = SharedImageSurface::new(reference_surf, SurfaceType::SRgb).unwrap();
 
-    compare_to_surface(&output_surf, &reference_surf, "snapshot_element");
+    compare_to_surface(&output_surf, &reference_surf, "render_layer");
 }
 
 #[test]
diff --git a/rsvg_internals/src/handle.rs b/rsvg_internals/src/handle.rs
index a5f745b8..fa653549 100644
--- a/rsvg_internals/src/handle.rs
+++ b/rsvg_internals/src/handle.rs
@@ -320,7 +320,7 @@ impl Handle {
             height: f64::from(dimensions.height),
         };
 
-        self.snapshot_element(cr, id, &viewport, dpi, is_testing)
+        self.render_layer(cr, id, &viewport, dpi, is_testing)
     }
 
     pub fn render_document(
@@ -330,10 +330,10 @@ impl Handle {
         dpi: Dpi,
         is_testing: bool,
     ) -> Result<(), RenderingError> {
-        self.snapshot_element(cr, None, viewport, dpi, is_testing)
+        self.render_layer(cr, None, viewport, dpi, is_testing)
     }
 
-    pub fn snapshot_element(
+    pub fn render_layer(
         &self,
         cr: &cairo::Context,
         id: Option<&str>,