Fix builder api, add save method

2 files changed, 44 insertions, 18 deletions

diff --git a/src/gif.rs b/src/gif.rs
index 36e64dd..5b58ed1 100644
--- a/src/gif.rs
+++ b/src/gif.rs
@@ -1,4 +1,9 @@
-use crate::{block::{extension::Extension, Block, ColorTable, ScreenDescriptor, Version}, writer::GifBuilder};
+use std::{fs::File, io::Write, path::Path};
+
+use crate::{
+    block::{extension::Extension, Block, ColorTable, ScreenDescriptor, Version},
+    writer::GifBuilder,
+};
 pub struct Gif {
     pub header: Version,
     pub screen_descriptor: ScreenDescriptor,
@@ -49,6 +54,10 @@ impl Gif {
 
         out
     }
+
+    pub fn save<P: AsRef<Path>>(&self, path: P) -> std::io::Result<()> {
+        File::create(path.as_ref())?.write_all(&self.to_vec())
+    }
 }
 
 /*struct FrameIterator {
@@ -150,11 +159,9 @@ pub mod gif {
                     .palette(colortable.try_into().unwrap())
                     .indicies(&indicies),
             )
-            .unwrap()
-            .image(ImageBuilder::new(4, 4).indicies(&indicies))
-            .unwrap();
+            .image(ImageBuilder::new(4, 4).indicies(&indicies));
 
-        let bytes = actual.build().to_vec();
+        let bytes = actual.build().unwrap().to_vec();
         assert_eq!(bytes, expected_out);
     }
 
@@ -179,10 +186,9 @@ pub mod gif {
                     .disposal_method(DisposalMethod::RestoreBackground)
                     .delay(64),
             )
-            .unwrap()
             .image(ImageBuilder::new(4, 4).indicies(&indicies))
-            .unwrap()
             .build()
+            .unwrap()
             .to_vec();
 
         std::fs::File::create("ah.gif")
diff --git a/src/writer/gifbuilder.rs b/src/writer/gifbuilder.rs
index ec3c304..1466f76 100644
--- a/src/writer/gifbuilder.rs
+++ b/src/writer/gifbuilder.rs
@@ -11,6 +11,7 @@ pub struct GifBuilder {
     background_color_index: u8,
     global_color_table: Option<ColorTable>,
     blocks: Vec<Block>,
+    error: Option<EncodingError>,
 }
 
 impl GifBuilder {
@@ -22,6 +23,7 @@ impl GifBuilder {
             background_color_index: 0,
             global_color_table: None,
             blocks: vec![],
+            error: None,
         }
     }
 
@@ -30,16 +32,24 @@ impl GifBuilder {
         self
     }
 
-    pub fn background_index(mut self, ind: u8) -> Result<Self, EncodingError> {
+    pub fn background_index(mut self, ind: u8) -> Self {
+        if self.error.is_some() {
+            return self;
+        }
+
         if self.global_color_table.is_none() {
-            Err(EncodingError::NoColorTable)
+            self.error = Some(EncodingError::NoColorTable);
         } else {
             self.background_color_index = ind;
-            Ok(self)
         }
+        self
     }
 
-    pub fn image(mut self, ib: ImageBuilder) -> Result<Self, EncodingError> {
+    pub fn image(mut self, ib: ImageBuilder) -> Self {
+        if self.error.is_some() {
+            return self;
+        }
+
         if ib.required_version() == Version::Gif89a {
             self.version = Version::Gif89a;
         }
@@ -48,8 +58,12 @@ impl GifBuilder {
             self.blocks.push(Block::Extension(gce.into()));
         }
 
-        self.blocks.push(Block::IndexedImage(ib.build()?));
-        Ok(self)
+        match ib.build() {
+            Ok(image) => self.blocks.push(Block::IndexedImage(image)),
+            Err(e) => self.error = Some(e),
+        }
+
+        self
     }
 
     /*pub fn extension(mut self, ext: Extension) -> Self {
@@ -57,11 +71,17 @@ impl GifBuilder {
         self
     }*/
 
-    pub fn repeat(&mut self, count: u16) {
-        self.blocks.push(Block::Extension(Extension::Looping(count)))
+    pub fn repeat(mut self, count: u16) -> Self {
+        self.blocks
+            .push(Block::Extension(Extension::Looping(count)));
+        self
     }
 
-    pub fn build(self) -> Gif {
+    pub fn build(self) -> Result<Gif, EncodingError> {
+        if let Some(error) = self.error {
+            return Err(error);
+        }
+
         let mut lsd = ScreenDescriptor {
             width: self.width,
             height: self.height,
@@ -76,11 +96,11 @@ impl GifBuilder {
             lsd.set_color_table_size((gct.len() - 1) as u8);
         }
 
-        Gif {
+        Ok(Gif {
             header: self.version,
             screen_descriptor: lsd,
             global_color_table: self.global_color_table,
             blocks: self.blocks,
-        }
+        })
     }
 }