From 5f2a0f03a6458a61e936f2aff7551886931c2237 Mon Sep 17 00:00:00 2001
From: Itamar <itamar8910@gmail.com>
Date: Tue, 29 Mar 2022 16:33:46 +0300
Subject: [PATCH] LibGUI: Add search API to TextEditor with highlighted results

This adds a search API to TextEditor.

The API that is similar to "find_text" of TextDocument (which is used
internally to do the search).

All search results (as well as the current one) are highlighted with
a "span collection", which is pretty neat :^)
---
 Userland/Libraries/LibGUI/TextEditor.cpp | 59 ++++++++++++++++++++++++
 Userland/Libraries/LibGUI/TextEditor.h   | 17 ++++++-
 2 files changed, 75 insertions(+), 1 deletion(-)

diff --git a/Userland/Libraries/LibGUI/TextEditor.cpp b/Userland/Libraries/LibGUI/TextEditor.cpp
index 36cbca5f88..45d8568cb3 100644
--- a/Userland/Libraries/LibGUI/TextEditor.cpp
+++ b/Userland/Libraries/LibGUI/TextEditor.cpp
@@ -1,6 +1,7 @@
 /*
  * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
  * Copyright (c) 2021, Jakob-Niklas See <git@nwex.de>
+ * Copyright (c) 2022, the SerenityOS developers.
  *
  * SPDX-License-Identifier: BSD-2-Clause
  */
@@ -2105,4 +2106,62 @@ void TextEditor::set_text_is_secret(bool text_is_secret)
     did_update_selection();
 }
 
+TextRange TextEditor::find_text(StringView needle, SearchDirection direction, GUI::TextDocument::SearchShouldWrap should_wrap, bool use_regex, bool match_case)
+{
+    GUI::TextRange range {};
+    if (direction == SearchDirection::Forward) {
+        range = document().find_next(needle,
+            m_search_result_index.has_value() ? m_search_results[*m_search_result_index].end() : GUI::TextPosition {},
+            should_wrap, use_regex, match_case);
+    } else {
+        range = document().find_previous(needle,
+            m_search_result_index.has_value() ? m_search_results[*m_search_result_index].start() : GUI::TextPosition {},
+            should_wrap, use_regex, match_case);
+    }
+
+    if (!range.is_valid()) {
+        reset_search_results();
+        return {};
+    }
+
+    auto all_results = document().find_all(needle, use_regex, match_case);
+    on_search_results(range, all_results);
+    return range;
+}
+
+void TextEditor::reset_search_results()
+{
+    m_search_result_index.clear();
+    m_search_results.clear();
+    document().set_spans(search_results_span_collection_index, {});
+    update();
+}
+
+void TextEditor::on_search_results(GUI::TextRange current, Vector<GUI::TextRange> all_results)
+{
+    m_search_result_index.clear();
+    m_search_results.clear();
+
+    set_cursor(current.start());
+    if (auto it = all_results.find(current); it->is_valid())
+        m_search_result_index = it.index();
+    m_search_results = move(all_results);
+
+    Vector<GUI::TextDocumentSpan> spans;
+    for (size_t i = 0; i < m_search_results.size(); ++i) {
+        auto& result = m_search_results[i];
+        GUI::TextDocumentSpan span;
+        span.range = result;
+        span.attributes.background_color = palette().hover_highlight();
+        span.attributes.color = Color::from_argb(0xff000000); // So text without spans from a highlighter will have color
+        if (i == m_search_result_index) {
+            span.attributes.bold = true;
+            span.attributes.underline = true;
+        }
+        spans.append(move(span));
+    }
+    document().set_spans(search_results_span_collection_index, move(spans));
+    update();
+}
+
 }
diff --git a/Userland/Libraries/LibGUI/TextEditor.h b/Userland/Libraries/LibGUI/TextEditor.h
index e3d2fa454e..ac3d536126 100644
--- a/Userland/Libraries/LibGUI/TextEditor.h
+++ b/Userland/Libraries/LibGUI/TextEditor.h
@@ -1,5 +1,6 @@
 /*
  * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
+ * Copyright (c) 2022, the SerenityOS developers.
  *
  * SPDX-License-Identifier: BSD-2-Clause
  */
@@ -213,6 +214,15 @@ public:
     void set_text_is_secret(bool text_is_secret);
     void force_rehighlight();
 
+    enum class SearchDirection {
+        Forward,
+        Backward,
+    };
+    TextRange find_text(StringView needle, SearchDirection, GUI::TextDocument::SearchShouldWrap, bool use_regex, bool match_case);
+    void reset_search_results();
+    Optional<size_t> search_result_index() const { return m_search_result_index; }
+    Vector<TextRange> const& search_results() const { return m_search_results; }
+
 protected:
     explicit TextEditor(Type = Type::MultiLine);
 
@@ -260,7 +270,6 @@ private:
     // ^Syntax::HighlighterClient
     virtual Vector<TextDocumentSpan>& spans() final { return document().spans(); }
     virtual Vector<TextDocumentSpan> const& spans() const final { return document().spans(); }
-    virtual void highlighter_did_set_spans(Vector<TextDocumentSpan> spans) final { document().set_spans(move(spans)); }
     virtual void set_span_at_index(size_t index, TextDocumentSpan span) final { document().set_span_at_index(index, move(span)); }
     virtual void highlighter_did_request_update() final { update(); }
     virtual String highlighter_did_request_text() const final { return text(); }
@@ -337,6 +346,9 @@ private:
     }
 
     virtual void will_execute(TextDocumentUndoCommand const&) { }
+    void on_search_results(GUI::TextRange current, Vector<GUI::TextRange> all_results);
+
+    static constexpr auto search_results_span_collection_index = 1;
 
     Type m_type { MultiLine };
     Mode m_mode { Editable };
@@ -408,6 +420,9 @@ private:
     RefPtr<Gfx::Bitmap> m_icon;
 
     bool m_text_is_secret { false };
+
+    Optional<size_t> m_search_result_index;
+    Vector<GUI::TextRange> m_search_results;
 };
 
 }