fix(cli): properly rewind / previous slide after reverse (#28)

* fix(cli): properly rewind / previous slide after reverse

Closes #24

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

Author: jeertmans

docs/source/conf.py

@@ -6,22 +6,21 @@
 # -- Project information -----------------------------------------------------
 # https://www.sphinx-doc.org/en/master/usage/configuration.html#project-information
 
-project = 'Manim Slides'
-copyright = '2022, Jérome Eertmans'
-author = 'Jérome Eertmans'
+project = "Manim Slides"
+copyright = "2022, Jérome Eertmans"
+author = "Jérome Eertmans"
 
 # -- General configuration ---------------------------------------------------
 # https://www.sphinx-doc.org/en/master/usage/configuration.html#general-configuration
 
 extensions = ["sphinx.ext.autodoc", "sphinx_click"]
 
-templates_path = ['_templates']
+templates_path = ["_templates"]
 exclude_patterns = []
 
 
-
 # -- Options for HTML output -------------------------------------------------
 # https://www.sphinx-doc.org/en/master/usage/configuration.html#options-for-html-output
 
-html_theme = 'furo'
-html_static_path = ['_static']
+html_theme = "furo"
+html_static_path = ["_static"]

manim_slides/present.py

@@ -134,6 +134,13 @@ def rewind_current_slide(self):
 
         self.current_cap.set(cv2.CAP_PROP_POS_FRAMES, 0)
 
+    def cancel_reverse(self):
+        """Cancels any effet produced by a reversed slide."""
+        if self.reverse:
+            self.reverse = False
+            self.reversed_animation = -1
+            self.release_cap()
+
     def reverse_current_slide(self):
         """Reverses current slide."""
         self.reverse = True
@@ -142,9 +149,7 @@ def reverse_current_slide(self):
     def load_next_slide(self):
         """Loads next slide."""
         if self.reverse:
-            self.reverse = False
-            self.reversed_animation = -1
-            self.release_cap()
+            self.cancel_reverse()
             self.rewind_current_slide()
         elif self.current_slide.is_last():
             self.current_slide.terminated = True
@@ -156,6 +161,7 @@ def load_next_slide(self):
 
     def load_previous_slide(self):
         """Loads previous slide."""
+        self.cancel_reverse()
         self.current_slide_index = max(0, self.current_slide_index - 1)
         self.rewind_current_slide()
 
@@ -425,7 +431,7 @@ def handle_key(self):
         elif self.config.BACK.match(key):
             if self.current_presentation.current_slide_index == 0:
                 if self.current_presentation_index == 0:
-                    self.current_presentation.rewind_current_slide()
+                    self.current_presentation.load_previous_slide()
                 else:
                     self.current_presentation_index -= 1
                     self.current_presentation.load_last_slide()
@@ -437,6 +443,7 @@ def handle_key(self):
             self.current_presentation.reverse_current_slide()
             self.state = State.PLAYING
         elif self.config.REWIND.match(key):
+            self.current_presentation.cancel_reverse()
             self.current_presentation.rewind_current_slide()
             self.state = State.PLAYING