Implement diff viewers

12 files changed, 43 insertions, 27 deletions

diff --git a/app/views/projects/diffs/_collapsed.html.haml b/app/views/projects/diffs/_collapsed.html.haml
new file mode 100644
index 00000000000..8772bd4705f
--- /dev/null
+++ b/app/views/projects/diffs/_collapsed.html.haml
@@ -0,0 +1,5 @@
+- diff_file = viewer.diff_file
+- url = url_for(params.merge(action: :diff_for_path, old_path: diff_file.old_path, new_path: diff_file.new_path, file_identifier: diff_file.file_identifier))
+.nothing-here-block.diff-collapsed{ data: { diff_for_path: url } }
+  This diff is collapsed.
+  %a.click-to-expand Click to expand it.
diff --git a/app/views/projects/diffs/_content.html.haml b/app/views/projects/diffs/_content.html.haml
index ec1c434a4b8..68f74f702ea 100644
--- a/app/views/projects/diffs/_content.html.haml
+++ b/app/views/projects/diffs/_content.html.haml
@@ -1,27 +1,2 @@
-- blob = diff_file.blob
-
 .diff-content
-  - if diff_file.too_large?
-    .nothing-here-block This diff could not be displayed because it is too large.
-  - elsif blob.truncated?
-    .nothing-here-block The file could not be displayed because it is too large.
-  - elsif blob.readable_text?
-    - if !diff_file.diffable?
-      .nothing-here-block This diff was suppressed by a .gitattributes entry.
-    - elsif diff_file.collapsed?
-      - url = url_for(params.merge(action: :diff_for_path, old_path: diff_file.old_path, new_path: diff_file.new_path, file_identifier: diff_file.file_identifier))
-      .nothing-here-block.diff-collapsed{ data: { diff_for_path: url } }
-        This diff is collapsed.
-        %a.click-to-expand
-          Click to expand it.
-    - elsif diff_file.diff_lines.length > 0
-      = render "projects/diffs/viewers/text", diff_file: diff_file
-    - else
-      - if diff_file.mode_changed?
-        .nothing-here-block File mode changed
-      - elsif diff_file.renamed_file?
-        .nothing-here-block File moved
-  - elsif blob.image?
-    = render "projects/diffs/viewers/image", diff_file: diff_file
-  - else
-    .nothing-here-block No preview for this file type
+  = render 'projects/diffs/viewer', viewer: diff_file.rich_viewer || diff_file.simple_viewer
diff --git a/app/views/projects/diffs/_render_error.html.haml b/app/views/projects/diffs/_render_error.html.haml
new file mode 100644
index 00000000000..47a9ac3ee6b
--- /dev/null
+++ b/app/views/projects/diffs/_render_error.html.haml
@@ -0,0 +1,6 @@
+.nothing-here-block
+  This #{viewer.switcher_title} could not be displayed because #{diff_render_error_reason(viewer)}.
+
+  You can
+  = diff_render_error_options(viewer).to_sentence(two_words_connector: ' or ', last_word_connector: ', or ').html_safe
+  instead.
diff --git a/app/views/projects/diffs/_viewer.html.haml b/app/views/projects/diffs/_viewer.html.haml
new file mode 100644
index 00000000000..5c4d1760871
--- /dev/null
+++ b/app/views/projects/diffs/_viewer.html.haml
@@ -0,0 +1,16 @@
+- hidden = local_assigns.fetch(:hidden, false)
+
+.diff-viewer{ data: { type: viewer.type }, class: ('hidden' if hidden) }
+  - if viewer.render_error
+    = render 'projects/diffs/render_error', viewer: viewer
+  - elsif viewer.collapsed?
+    = render 'projects/diffs/collapsed', viewer: viewer
+  - else
+    - viewer.prepare!
+
+    -# In the rare case where the first kilobyte of the file looks like text,
+    -# but the file turns out to actually be binary after loading all data,
+    -# we fall back on the binary No Preview viewer.
+    - viewer = DiffViewer::NoPreview.new(viewer.diff_file) if viewer.binary_detected_after_load?
+
+    = render viewer.partial_path, viewer: viewer
diff --git a/app/views/projects/diffs/viewers/_added.html.haml b/app/views/projects/diffs/viewers/_added.html.haml
new file mode 100644
index 00000000000..8004fe16688
--- /dev/null
+++ b/app/views/projects/diffs/viewers/_added.html.haml
@@ -0,0 +1,2 @@
+.nothing-here-block
+  File added
diff --git a/app/views/projects/diffs/viewers/_deleted.html.haml b/app/views/projects/diffs/viewers/_deleted.html.haml
new file mode 100644
index 00000000000..0ac7b4ca8f6
--- /dev/null
+++ b/app/views/projects/diffs/viewers/_deleted.html.haml
@@ -0,0 +1,2 @@
+.nothing-here-block
+  File deleted
diff --git a/app/views/projects/diffs/viewers/_image.html.haml b/app/views/projects/diffs/viewers/_image.html.haml
index ea75373581e..19d08181223 100644
--- a/app/views/projects/diffs/viewers/_image.html.haml
+++ b/app/views/projects/diffs/viewers/_image.html.haml
@@ -1,3 +1,4 @@
+- diff_file = viewer.diff_file
 - blob = diff_file.blob
 - old_blob = diff_file.old_blob
 - blob_raw_path = diff_file_blob_raw_path(diff_file)
diff --git a/app/views/projects/diffs/viewers/_mode_changed.html.haml b/app/views/projects/diffs/viewers/_mode_changed.html.haml
new file mode 100644
index 00000000000..69bc96bbdad
--- /dev/null
+++ b/app/views/projects/diffs/viewers/_mode_changed.html.haml
@@ -0,0 +1,3 @@
+- diff_file = viewer.diff_file
+.nothing-here-block
+  File mode changed from #{diff_file.a_mode} to #{diff_file.b_mode}
diff --git a/app/views/projects/diffs/viewers/_no_preview.html.haml b/app/views/projects/diffs/viewers/_no_preview.html.haml
new file mode 100644
index 00000000000..befe070af2b
--- /dev/null
+++ b/app/views/projects/diffs/viewers/_no_preview.html.haml
@@ -0,0 +1,2 @@
+.nothing-here-block
+  No preview for this file type
diff --git a/app/views/projects/diffs/viewers/_not_diffable.html.haml b/app/views/projects/diffs/viewers/_not_diffable.html.haml
new file mode 100644
index 00000000000..b2c677ec59c
--- /dev/null
+++ b/app/views/projects/diffs/viewers/_not_diffable.html.haml
@@ -0,0 +1,2 @@
+.nothing-here-block
+  This diff was suppressed by a .gitattributes entry.
diff --git a/app/views/projects/diffs/viewers/_renamed.html.haml b/app/views/projects/diffs/viewers/_renamed.html.haml
new file mode 100644
index 00000000000..ef05ee38d8d
--- /dev/null
+++ b/app/views/projects/diffs/viewers/_renamed.html.haml
@@ -0,0 +1,2 @@
+.nothing-here-block
+  File moved
diff --git a/app/views/projects/diffs/viewers/_text.html.haml b/app/views/projects/diffs/viewers/_text.html.haml
index 120d3540223..509e68598c9 100644
--- a/app/views/projects/diffs/viewers/_text.html.haml
+++ b/app/views/projects/diffs/viewers/_text.html.haml
@@ -1,5 +1,5 @@
+- diff_file = viewer.diff_file
 - blob = diff_file.blob
-- blob.load_all_data!
 - total_lines = blob.lines.size
 - total_lines -= 1 if total_lines > 0 && blob.lines.last.blank?
 - if diff_view == :parallel