basic features like streaming, stopping, simple formatting, etc.

Cargo.toml

@@ -4,10 +4,17 @@ version = "0.1.0"
 edition = "2021"
 
 [dependencies]
-gtk4 = { version = "0.9", features = ["v4_6"] }
-tokio = { version = "1.0", features = ["full"] }
+# GTK4 and GLib
+gtk4 = { version = "0.9", features = ["v4_12"] }
+
+# HTTP client with JSON support
+reqwest = { version = "0.12", default-features = false, features = ["rustls-tls", "json", "stream"] }
+
+# Async runtime and utilities
+tokio = { version = "1.0", features = ["rt-multi-thread", "time"] }
+futures-util = "0.3"
+async-channel = "2.1"
+
+# Serialization
 serde = { version = "1.0", features = ["derive"] }
-serde_json = "1.0"
-reqwest = { version = "0.12", features = ["json"] }
-pango = "0.20"
-regex = "1.0"
+serde_json = "1.0"

src/api.rs

@@ -1,18 +1,24 @@
 use std::sync::{Arc, Mutex};
-use crate::types::{ChatMessage, ChatRequest, ChatResponse, ModelInfo, ModelsResponse};
+use futures_util::StreamExt;
+use tokio::time::{timeout, Duration};
+use crate::types::{ChatMessage, ChatRequest, ModelInfo, ModelsResponse, StreamResponse};
 
-pub async fn fetch_models(base_url: &str) -> Result<Vec<ModelInfo>, Box<dyn std::error::Error>> {
+pub async fn fetch_models(base_url: &str) -> Result<Vec<ModelInfo>, Box<dyn std::error::Error + Send + Sync>> {
     let url = format!("{}/api/tags", base_url);
-    let response = reqwest::get(&url).await?;
+    
+    // Add timeout to prevent hanging
+    let response = timeout(Duration::from_secs(10), reqwest::get(&url)).await??;
     let models_response: ModelsResponse = response.json().await?;
     Ok(models_response.models)
 }
 
-pub async fn send_chat_request(
+pub async fn send_chat_request_streaming(
     base_url: &str,
     model: &str,
     conversation: &Arc<Mutex<Vec<ChatMessage>>>,
-) -> Result<String, Box<dyn std::error::Error>> {
+    token_sender: async_channel::Sender<String>,
+    thinking_enabled: bool,
+) -> Result<String, Box<dyn std::error::Error + Send + Sync>> {
     let messages = {
         let conversation = conversation.lock().unwrap();
         conversation.iter().cloned().collect::<Vec<_>>()
@@ -21,10 +27,14 @@ pub async fn send_chat_request(
     let request = ChatRequest {
         model: model.to_string(),
         messages,
-        stream: false,
+        stream: true,
+        think: if thinking_enabled { Some(true) } else { Some(false) },
     };
 
-    let client = reqwest::Client::new();
+    let client = reqwest::Client::builder()
+        .timeout(Duration::from_secs(120)) // 2 minute timeout
+        .build()?;
+    
     let url = format!("{}/api/chat", base_url);
     
     let response = client
@@ -33,6 +43,82 @@ pub async fn send_chat_request(
         .send()
         .await?;
 
-    let chat_response: ChatResponse = response.json().await?;
-    Ok(chat_response.message.content)
-}
+    if !response.status().is_success() {
+        return Err(format!("API request failed with status: {}", response.status()).into());
+    }
+
+    let mut stream = response.bytes_stream();
+    let mut full_response = String::new();
+    let mut current_batch = String::new();
+    let mut tokens_since_last_send = 0;
+    const BATCH_SIZE: usize = 20; // Reasonable batch size
+    const BATCH_TIMEOUT: Duration = Duration::from_millis(100);
+
+    let mut last_send = tokio::time::Instant::now();
+
+    while let Some(chunk_result) = stream.next().await {
+        let chunk = chunk_result?;
+        let text = String::from_utf8_lossy(&chunk);
+        
+        for line in text.lines() {
+            if line.trim().is_empty() {
+                continue;
+            }
+            
+            match serde_json::from_str::<StreamResponse>(line) {
+                Ok(stream_response) => {
+                    let token = stream_response.message.content;
+                    
+                    if !token.is_empty() {
+                        full_response.push_str(&token);
+                        current_batch.push_str(&token);
+                        tokens_since_last_send += 1;
+                    }
+                    
+                    // Send batch if conditions are met
+                    let should_send = tokens_since_last_send >= BATCH_SIZE 
+                        || last_send.elapsed() >= BATCH_TIMEOUT 
+                        || stream_response.done;
+                    
+                    if should_send && !current_batch.is_empty() {
+                        // Use non-blocking send with async-channel
+                        match token_sender.send(current_batch.clone()).await {
+                            Ok(_) => {
+                                current_batch.clear();
+                                tokens_since_last_send = 0;
+                                last_send = tokio::time::Instant::now();
+                            }
+                            Err(_) => {
+                                // Channel closed, stop sending but continue processing
+                                break;
+                            }
+                        }
+                    }
+                    
+                    if stream_response.done {
+                        break;
+                    }
+                }
+                Err(parse_error) => {
+                    // Log parse errors but continue processing
+                    eprintln!("Failed to parse streaming response: {} (line: {})", parse_error, line);
+                    continue;
+                }
+            }
+        }
+    }
+    
+    // Send any remaining tokens in the batch
+    if !current_batch.is_empty() {
+        let _ = token_sender.send(current_batch).await;
+    }
+
+    // async_channel automatically closes when sender is dropped
+    drop(token_sender);
+
+    if full_response.is_empty() {
+        return Err("No response received from the model".into());
+    }
+
+    Ok(full_response)
+}

src/main.rs

@@ -5,14 +5,12 @@ mod ui;
 mod api;
 mod types;
 mod state;
-
-use state::AppState;
+mod markdown_processor;
 
 const APP_ID: &str = "com.example.ollama-chat";
 
-#[tokio::main]
-async fn main() -> glib::ExitCode {
+fn main() -> glib::ExitCode {
     let app = Application::builder().application_id(APP_ID).build();
     app.connect_activate(ui::build_ui);
     app.run()
-}
+}

src/markdown_processor.rs

@@ -0,0 +1,351 @@
+use gtk4::prelude::*;
+use gtk4::{TextBuffer, TextTag, TextTagTable};
+use std::collections::HashMap;
+
+pub struct MarkdownProcessor {
+    h1_tag: TextTag,
+    h2_tag: TextTag,
+    h3_tag: TextTag,
+    h4_tag: TextTag,
+    h5_tag: TextTag,
+    h6_tag: TextTag,
+    bold_tag: TextTag,
+    italic_tag: TextTag,
+    code_tag: TextTag,
+}
+
+impl MarkdownProcessor {
+    pub fn new() -> Self {
+        // Heading tags
+        let h1_tag = TextTag::new(Some("h1"));
+        h1_tag.set_weight(700);
+        h1_tag.set_line_height(1.4);
+        h1_tag.set_scale(1.5);
+        
+        let h2_tag = TextTag::new(Some("h2"));
+        h2_tag.set_weight(700);
+        h2_tag.set_line_height(1.4);
+        h2_tag.set_scale(1.4);
+        
+        let h3_tag = TextTag::new(Some("h3"));
+        h3_tag.set_weight(700);
+        h3_tag.set_line_height(1.2);
+        h3_tag.set_scale(1.3);
+        
+        let h4_tag = TextTag::new(Some("h4"));
+        h4_tag.set_weight(700);
+        h4_tag.set_line_height(1.2);
+        h4_tag.set_scale(1.2);
+        
+        let h5_tag = TextTag::new(Some("h5"));
+        h5_tag.set_weight(700);
+        h5_tag.set_line_height(1.2);
+        h5_tag.set_scale(1.1);
+        
+        let h6_tag = TextTag::new(Some("h6"));
+        h6_tag.set_weight(700);
+        h6_tag.set_line_height(1.2);
+        h6_tag.set_scale(1.0);
+        
+        // Inline formatting tags
+        let bold_tag = TextTag::new(Some("bold"));
+        bold_tag.set_weight(700);
+        
+        let italic_tag = TextTag::new(Some("italic"));
+        italic_tag.set_style(gtk4::pango::Style::Italic);
+        
+        let code_tag = TextTag::new(Some("code"));
+        code_tag.set_property("font", &"monospace");
+        code_tag.set_scale(0.9);
+        
+        Self {
+            h1_tag,
+            h2_tag,
+            h3_tag,
+            h4_tag,
+            h5_tag,
+            h6_tag,
+            bold_tag,
+            italic_tag,
+            code_tag,
+        }
+    }
+    
+    pub fn setup_tags(&self, buffer: &TextBuffer) {
+        let tag_table = buffer.tag_table();
+        tag_table.add(&self.h1_tag);
+        tag_table.add(&self.h2_tag);
+        tag_table.add(&self.h3_tag);
+        tag_table.add(&self.h4_tag);
+        tag_table.add(&self.h5_tag);
+        tag_table.add(&self.h6_tag);
+        tag_table.add(&self.bold_tag);
+        tag_table.add(&self.italic_tag);
+        tag_table.add(&self.code_tag);
+    }
+    
+    pub fn insert_formatted_text(&self, buffer: &TextBuffer, text: &str, iter: &mut gtk4::TextIter) {
+        // Process the text line by line to handle headings and inline formatting
+        let lines: Vec<&str> = text.lines().collect();
+        
+        for (i, line) in lines.iter().enumerate() {
+            // Check if this line is a heading
+            if let Some(heading) = self.parse_heading(line) {
+                let tag = match heading.level {
+                    1 => &self.h1_tag,
+                    2 => &self.h2_tag,
+                    3 => &self.h3_tag,
+                    4 => &self.h4_tag,
+                    5 => &self.h5_tag,
+                    _ => &self.h6_tag,
+                };
+                
+                buffer.insert(iter, "\n");
+                buffer.insert_with_tags(iter, &heading.content, &[tag]);
+                buffer.insert(iter, "\n");
+            } else {
+                // Process inline formatting for non-heading lines
+                self.insert_formatted_line(buffer, line, iter);
+                
+                // Add newline if not the last line
+                if i < lines.len() - 1 {
+                    buffer.insert(iter, "\n");
+                }
+            }
+        }
+    }
+    
+    fn insert_formatted_line(&self, buffer: &TextBuffer, line: &str, iter: &mut gtk4::TextIter) {
+        let segments = self.parse_inline_formatting(line);
+        
+        for segment in segments {
+            match segment.format_type {
+                FormatType::Plain => {
+                    buffer.insert(iter, &segment.content);
+                }
+                FormatType::Bold => {
+                    buffer.insert_with_tags(iter, &segment.content, &[&self.bold_tag]);
+                }
+                FormatType::Italic => {
+                    buffer.insert_with_tags(iter, &segment.content, &[&self.italic_tag]);
+                }
+                FormatType::Code => {
+                    buffer.insert_with_tags(iter, &segment.content, &[&self.code_tag]);
+                }
+                FormatType::BoldItalic => {
+                    buffer.insert_with_tags(iter, &segment.content, &[&self.bold_tag, &self.italic_tag]);
+                }
+                FormatType::Heading(_) => {
+                    // This shouldn't happen in inline processing
+                    buffer.insert(iter, &segment.content);
+                }
+            }
+        }
+    }
+    
+    fn parse_heading(&self, line: &str) -> Option<HeadingInfo> {
+        if line.starts_with('#') {
+            let hash_count = line.chars().take_while(|&c| c == '#').count();
+            
+            if hash_count <= 6 && line.len() > hash_count + 1 && line.chars().nth(hash_count) == Some(' ') {
+                let content = &line[hash_count + 1..].trim();
+                return Some(HeadingInfo {
+                    level: hash_count,
+                    content: content.to_string(),
+                });
+            }
+        }
+        None
+    }
+    
+    fn parse_inline_formatting(&self, text: &str) -> Vec<TextSegment> {
+        let mut segments = Vec::new();
+        let mut current_pos = 0;
+        let chars: Vec<char> = text.chars().collect();
+        
+        while current_pos < chars.len() {
+            // Look for the next formatting marker
+            if let Some((marker_pos, marker_type, marker_len)) = self.find_next_marker(&chars, current_pos) {
+                // Add any plain text before the marker
+                if marker_pos > current_pos {
+                    let plain_text: String = chars[current_pos..marker_pos].iter().collect();
+                    if !plain_text.is_empty() {
+                        segments.push(TextSegment {
+                            content: plain_text,
+                            format_type: FormatType::Plain,
+                        });
+                    }
+                }
+                
+                // Find the closing marker
+                if let Some((close_pos, close_len)) = self.find_closing_marker(&chars, marker_pos + marker_len, &marker_type) {
+                    let content_start = marker_pos + marker_len;
+                    let content_end = close_pos;
+                    
+                    if content_start < content_end {
+                        let content: String = chars[content_start..content_end].iter().collect();
+                        segments.push(TextSegment {
+                            content,
+                            format_type: marker_type,
+                        });
+                    }
+                    
+                    current_pos = close_pos + close_len;
+                } else {
+                    // No closing marker found, treat as plain text
+                    let plain_char: String = chars[marker_pos..marker_pos + marker_len].iter().collect();
+                    segments.push(TextSegment {
+                        content: plain_char,
+                        format_type: FormatType::Plain,
+                    });
+                    current_pos = marker_pos + marker_len;
+                }
+            } else {
+                // No more markers, add the rest as plain text
+                let remaining: String = chars[current_pos..].iter().collect();
+                if !remaining.is_empty() {
+                    segments.push(TextSegment {
+                        content: remaining,
+                        format_type: FormatType::Plain,
+                    });
+                }
+                break;
+            }
+        }
+        
+        segments
+    }
+    
+    fn find_next_marker(&self, chars: &[char], start_pos: usize) -> Option<(usize, FormatType, usize)> {
+        let mut earliest_pos = None;
+        let mut earliest_type = FormatType::Plain;
+        let mut earliest_len = 0;
+        
+        for pos in start_pos..chars.len() {
+            // Check for inline code (backticks)
+            if chars[pos] == '`' {
+                if earliest_pos.is_none() || pos < earliest_pos.unwrap() {
+                    earliest_pos = Some(pos);
+                    earliest_type = FormatType::Code;
+                    earliest_len = 1;
+                }
+                break; // Prioritize code as it can contain other markers
+            }
+            
+            // Check for bold/italic markers
+            if pos + 1 < chars.len() {
+                // Check for ** (bold) or *** (bold+italic)
+                if chars[pos] == '*' && chars[pos + 1] == '*' {
+                    if pos + 2 < chars.len() && chars[pos + 2] == '*' {
+                        // *** bold+italic
+                        if earliest_pos.is_none() || pos < earliest_pos.unwrap() {
+                            earliest_pos = Some(pos);
+                            earliest_type = FormatType::BoldItalic;
+                            earliest_len = 3;
+                        }
+                    } else {
+                        // ** bold
+                        if earliest_pos.is_none() || pos < earliest_pos.unwrap() {
+                            earliest_pos = Some(pos);
+                            earliest_type = FormatType::Bold;
+                            earliest_len = 2;
+                        }
+                    }
+                    break;
+                }
+                
+                // Check for __ (bold)
+                if chars[pos] == '_' && chars[pos + 1] == '_' {
+                    if earliest_pos.is_none() || pos < earliest_pos.unwrap() {
+                        earliest_pos = Some(pos);
+                        earliest_type = FormatType::Bold;
+                        earliest_len = 2;
+                    }
+                    break;
+                }
+            }
+            
+            // Check for single * or _ (italic)
+            if chars[pos] == '*' || chars[pos] == '_' {
+                // Make sure it's not part of a double marker
+                let is_single = (pos == 0 || chars[pos - 1] != chars[pos]) &&
+                               (pos + 1 >= chars.len() || chars[pos + 1] != chars[pos]);
+                
+                if is_single && (earliest_pos.is_none() || pos < earliest_pos.unwrap()) {
+                    earliest_pos = Some(pos);
+                    earliest_type = FormatType::Italic;
+                    earliest_len = 1;
+                }
+            }
+        }
+        
+        earliest_pos.map(|pos| (pos, earliest_type, earliest_len))
+    }
+    
+    fn find_closing_marker(&self, chars: &[char], start_pos: usize, marker_type: &FormatType) -> Option<(usize, usize)> {
+        match marker_type {
+            FormatType::Code => {
+                // Look for closing backtick
+                for pos in start_pos..chars.len() {
+                    if chars[pos] == '`' {
+                        return Some((pos, 1));
+                    }
+                }
+            }
+            FormatType::Bold => {
+                // Look for closing ** or __
+                for pos in start_pos..chars.len().saturating_sub(1) {
+                    if (chars[pos] == '*' && chars[pos + 1] == '*') ||
+                       (chars[pos] == '_' && chars[pos + 1] == '_') {
+                        return Some((pos, 2));
+                    }
+                }
+            }
+            FormatType::Italic => {
+                // Look for closing * or _
+                for pos in start_pos..chars.len() {
+                    if chars[pos] == '*' || chars[pos] == '_' {
+                        // Make sure it's not part of a double marker
+                        let is_single = (pos == 0 || chars[pos - 1] != chars[pos]) &&
+                                       (pos + 1 >= chars.len() || chars[pos + 1] != chars[pos]);
+                        if is_single {
+                            return Some((pos, 1));
+                        }
+                    }
+                }
+            }
+            FormatType::BoldItalic => {
+                // Look for closing ***
+                for pos in start_pos..chars.len().saturating_sub(2) {
+                    if chars[pos] == '*' && chars[pos + 1] == '*' && chars[pos + 2] == '*' {
+                        return Some((pos, 3));
+                    }
+                }
+            }
+            _ => {}
+        }
+        None
+    }
+}
+
+#[derive(Debug, Clone)]
+struct TextSegment {
+    content: String,
+    format_type: FormatType,
+}
+
+#[derive(Debug, Clone)]
+struct HeadingInfo {
+    level: usize,
+    content: String,
+}
+
+#[derive(Debug, Clone, PartialEq)]
+enum FormatType {
+    Plain,
+    Heading(usize),
+    Bold,
+    Italic,
+    Code,
+    BoldItalic,
+}

src/state.rs

@@ -5,6 +5,8 @@ use crate::types::ChatMessage;
 pub struct AppState {
     pub conversation: Arc<Mutex<Vec<ChatMessage>>>,
     pub ollama_url: String,
+    pub thinking_enabled: Arc<Mutex<bool>>,
+    pub current_request_handle: Arc<Mutex<Option<tokio::task::JoinHandle<()>>>>,
 }
 
 impl Default for AppState {
@@ -12,6 +14,8 @@ impl Default for AppState {
         Self {
             conversation: Arc::new(Mutex::new(Vec::new())),
             ollama_url: "http://localhost:11434".to_string(),
+            thinking_enabled: Arc::new(Mutex::new(false)),
+            current_request_handle: Arc::new(Mutex::new(None)),
         }
     }
-}
+}

src/types.rs

@@ -11,6 +11,8 @@ pub struct ChatRequest {
     pub model: String,
     pub messages: Vec<ChatMessage>,
     pub stream: bool,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub think: Option<bool>,
 }
 
 #[derive(Debug, Serialize, Deserialize)]
@@ -20,6 +22,14 @@ pub struct ChatResponse {
     pub done: bool,
 }
 
+#[derive(Debug, Serialize, Deserialize)]
+pub struct StreamResponse {
+    pub model: String,
+    pub created_at: String,
+    pub message: ChatMessage,
+    pub done: bool,
+}
+
 #[derive(Debug, Serialize, Deserialize)]
 pub struct ModelInfo {
     pub name: String,
@@ -28,4 +38,4 @@ pub struct ModelInfo {
 #[derive(Debug, Serialize, Deserialize)]
 pub struct ModelsResponse {
     pub models: Vec<ModelInfo>,
-}
+}

src/ui.rs

@@ -1,11 +1,21 @@
 use gtk4::prelude::*;
-use gtk4::{glib, Application, ApplicationWindow, Button, ComboBoxText, Label, ScrolledWindow, TextView, TextBuffer, TextTag, TextTagTable, Orientation, PolicyType, WrapMode, Align};
+use gtk4::{glib, Application, ApplicationWindow, Button, DropDown, Label, ScrolledWindow, TextView, TextBuffer, StringList, Orientation, PolicyType, WrapMode, Align, CheckButton};
 use gtk4::Box as GtkBox;
-use glib::spawn_future_local;
+use glib::{spawn_future_local, clone};
+use std::sync::{OnceLock, Arc, Mutex};
+use tokio::runtime::Runtime;
 
 use crate::api;
 use crate::state::AppState;
 use crate::types::ChatMessage;
+use crate::markdown_processor::MarkdownProcessor;
+
+// enum to track button state
+#[derive(Clone, PartialEq)]
+enum ButtonState {
+    Send,
+    Stop,
+}
 
 pub fn build_ui(app: &Application) {
     let window = ApplicationWindow::builder()
@@ -15,30 +25,47 @@ pub fn build_ui(app: &Application) {
         .default_height(700)
         .build();
 
-    // Apply minimal CSS for larger fonts and spacing
     let css_provider = gtk4::CssProvider::new();
-    css_provider.load_from_data(
+    css_provider.load_from_string(
         r#"
         window {
             font-size: 16px;
         }
         
         .chat-text {
-            font-size: 16px;
+            font-size: 18px;
             padding: 24px;
+            border-radius: 12px;
         }
         
         .input-text {
             font-size: 16px;
             padding: 16px;
+            border-radius: 12px;
         }
         
         button {
             font-size: 16px;
             padding: 16px 24px;
+            border-radius: 12px;
         }
         
-        combobox {
+        .stop-button {
+            background-color: #dc3545;
+            color: white;
+        }
+        
+        .send-button {
+            background-color: #007bff;
+            color: white;
+        }
+        
+        dropdown {
+            font-size: 16px;
+            border-radius: 12px;
+        }
+        
+        checkbutton {
             font-size: 16px;
         }
         "#
@@ -62,7 +89,7 @@ pub fn build_ui(app: &Application) {
     chat_scroll.set_policy(PolicyType::Never, PolicyType::Automatic);
     chat_scroll.set_vexpand(true);
     
-    let (chat_view, chat_buffer) = create_chat_view();
+    let (chat_view, chat_buffer, markdown_processor) = create_chat_view();
     chat_scroll.set_child(Some(&chat_view));
 
     // Input area
@@ -83,23 +110,37 @@ pub fn build_ui(app: &Application) {
     let input_buffer = input_view.buffer();
     input_scroll.set_child(Some(&input_view));
     
-    let send_button = Button::with_label("Send");
-    send_button.set_valign(Align::End);
+    // Single button that changes between Send and Stop
+    let action_button = Button::with_label("Send");
+    action_button.add_css_class("send-button");
+    action_button.set_valign(Align::End);
+    
+    // Track button state
+    let button_state = Arc::new(Mutex::new(ButtonState::Send));
     
     input_area_container.append(&input_scroll);
-    input_area_container.append(&send_button);
+    input_area_container.append(&action_button);
 
     // Bottom controls
     let controls_container = GtkBox::new(Orientation::Horizontal, 16);
     
     let model_label = Label::new(Some("Model:"));
-    let model_combo = ComboBoxText::new();
+    
+    // Create StringList to hold model names
+    let model_list = StringList::new(&[]);
+    let model_dropdown = DropDown::new(Some(model_list.clone()), None::<gtk4::Expression>);
+    
+    // Add thinking checkbox
+    let thinking_checkbox = CheckButton::with_label("Think");
+    thinking_checkbox.set_tooltip_text(Some("Enable thinking mode for reasoning models (e.g., deepseek-r1)"));
+    
     let status_label = Label::new(Some("Ready"));
     status_label.set_hexpand(true);
     status_label.set_halign(Align::End);
 
     controls_container.append(&model_label);
-    controls_container.append(&model_combo);
+    controls_container.append(&model_dropdown);
+    controls_container.append(&thinking_checkbox);
     controls_container.append(&status_label);
 
     input_container.append(&input_area_container);
@@ -114,120 +155,184 @@ pub fn build_ui(app: &Application) {
     let app_state = AppState::default();
 
     // Load available models
-    load_models(model_combo.clone(), status_label.clone(), app_state.clone());
+    load_models(model_list.clone(), model_dropdown.clone(), status_label.clone(), app_state.clone());
 
     // Set up event handlers
-    setup_send_handler(
-        send_button.clone(),
+    setup_action_button_handler(
+        action_button.clone(),
+        button_state.clone(),
         input_buffer,
-        chat_buffer,
-        model_combo,
-        status_label,
-        app_state,
+        chat_buffer.clone(),
+        model_dropdown,
+        model_list,
+        thinking_checkbox.clone(),
+        status_label.clone(),
+        app_state.clone(),
+        markdown_processor,
+        chat_scroll.clone(),
     );
     
-    setup_keyboard_shortcut(input_view, send_button);
+    // Connect thinking checkbox to app state
+    setup_thinking_checkbox_handler(thinking_checkbox, app_state.clone());
+    
+    setup_keyboard_shortcut(input_view, action_button.clone(), button_state.clone());
 
     window.present();
 }
 
-fn create_chat_view() -> (TextView, TextBuffer) {
-    let chat_view = TextView::new();
-    chat_view.set_editable(false);
-    chat_view.set_cursor_visible(false);
-    chat_view.set_wrap_mode(WrapMode::WordChar);
-    chat_view.add_css_class("chat-text");
-    
-    let chat_buffer = TextBuffer::new(None);
-    chat_view.set_buffer(Some(&chat_buffer));
-    
-    (chat_view, chat_buffer)
-}
-
-fn load_models(combo: ComboBoxText, status_label: Label, app_state: AppState) {
-    status_label.set_text("Loading models...");
-    
-    let combo_weak = combo.downgrade();
-    let status_weak = status_label.downgrade();
-    
-    spawn_future_local(async move {
-        match api::fetch_models(&app_state.ollama_url).await {
-            Ok(models) => {
-                if let (Some(combo), Some(status_label)) = (combo_weak.upgrade(), status_weak.upgrade()) {
-                    combo.remove_all();
-                    for model in models {
-                        combo.append_text(&model.name);
-                    }
-                    if combo.active().is_none() && combo.model().unwrap().iter_n_children(None) > 0 {
-                        combo.set_active(Some(0));
-                    }
-                    status_label.set_text("Ready");
-                }
-            }
-            Err(e) => {
-                if let Some(status_label) = status_weak.upgrade() {
-                    status_label.set_text(&format!("Error loading models: {}", e));
-                }
-            }
+// Helper function to update button appearance
+fn update_button_state(button: &Button, state: ButtonState) {
+    match state {
+        ButtonState::Send => {
+            button.set_label("Send");
+            button.remove_css_class("stop-button");
+            button.add_css_class("send-button");
         }
-    });
+        ButtonState::Stop => {
+            button.set_label("Stop");
+            button.remove_css_class("send-button");
+            button.add_css_class("stop-button");
+        }
+    }
 }
 
-fn setup_send_handler(
-    send_button: Button,
+fn setup_action_button_handler(
+    action_button: Button,
+    button_state: Arc<Mutex<ButtonState>>,
     input_buffer: TextBuffer,
     chat_buffer: TextBuffer,
-    model_combo: ComboBoxText,
+    model_dropdown: DropDown,
+    model_list: StringList,
+    thinking_checkbox: CheckButton,
     status_label: Label,
     app_state: AppState,
+    markdown_processor: Arc<MarkdownProcessor>,
+    chat_scroll: ScrolledWindow,
 ) {
-    send_button.connect_clicked(move |_| {
-        let start_iter = input_buffer.start_iter();
-        let end_iter = input_buffer.end_iter();
-        let text = input_buffer.text(&start_iter, &end_iter, false);
-        
-        if text.trim().is_empty() {
-            return;
+    action_button.connect_clicked(clone!(
+        #[weak] input_buffer,
+        #[weak] chat_buffer,
+        #[weak] model_dropdown,
+        #[weak] model_list,
+        #[weak] thinking_checkbox,
+        #[weak] status_label,
+        #[weak] action_button,
+        #[strong] button_state,
+        #[strong] markdown_processor,
+        move |_| {
+            let current_state = {
+                let state = button_state.lock().unwrap();
+                state.clone()
+            };
+            
+            match current_state {
+                ButtonState::Send => {
+                    // Handle send logic
+                    let start_iter = input_buffer.start_iter();
+                    let end_iter = input_buffer.end_iter();
+                    let text = input_buffer.text(&start_iter, &end_iter, false);
+                    
+                    if text.trim().is_empty() {
+                        return;
+                    }
+                    
+                    // Get selected model
+                    let selected_idx = model_dropdown.selected();
+                    if selected_idx == gtk4::INVALID_LIST_POSITION {
+                        status_label.set_text("Please select a model first");
+                        return;
+                    }
+                    
+                    let model = match model_list.string(selected_idx) {
+                        Some(m) => m.to_string(),
+                        None => {
+                            status_label.set_text("Invalid model selection");
+                            return;
+                        }
+                    };
+                    
+                    // Get thinking checkbox state
+                    let thinking_enabled = thinking_checkbox.is_active();
+                    
+                    input_buffer.delete(&mut input_buffer.start_iter(), &mut input_buffer.end_iter());
+                    
+                    // Change button to Stop state
+                    {
+                        let mut state = button_state.lock().unwrap();
+                        *state = ButtonState::Stop;
+                    }
+                    update_button_state(&action_button, ButtonState::Stop);
+                    
+                    send_message(
+                        text.to_string(),
+                        model,
+                        thinking_enabled,
+                        chat_buffer.clone(),
+                        chat_scroll.clone(),
+                        status_label.clone(),
+                        action_button.clone(),
+                        button_state.clone(),
+                        app_state.clone(),
+                        markdown_processor.clone(),
+                    );
+                }
+                ButtonState::Stop => {
+                    // Handle stop logic
+                    let mut handle = app_state.current_request_handle.lock().unwrap();
+                    if let Some(task) = handle.take() {
+                        task.abort();
+                        status_label.set_text("Generation stopped");
+                        
+                        // Change button back to Send state
+                        {
+                            let mut state = button_state.lock().unwrap();
+                            *state = ButtonState::Send;
+                        }
+                        update_button_state(&action_button, ButtonState::Send);
+                    }
+                }
+            }
         }
-        
-        let selected_model = model_combo.active_text();
-        if selected_model.is_none() {
-            status_label.set_text("Please select a model first");
-            return;
-        }
-        
-        let model = selected_model.unwrap().to_string();
-        input_buffer.delete(&mut input_buffer.start_iter(), &mut input_buffer.end_iter());
-        
-        send_message(
-            text.to_string(),
-            model,
-            chat_buffer.clone(),
-            status_label.clone(),
-            app_state.clone(),
-        );
-    });
+    ));
 }
 
-fn setup_keyboard_shortcut(input_view: TextView, send_button: Button) {
+fn setup_keyboard_shortcut(input_view: TextView, action_button: Button, button_state: Arc<Mutex<ButtonState>>) {
     let input_controller = gtk4::EventControllerKey::new();
-    input_controller.connect_key_pressed(move |_, key, _, modifier| {
-        if key == gtk4::gdk::Key::Return && modifier.contains(gtk4::gdk::ModifierType::CONTROL_MASK) {
-            send_button.emit_clicked();
-            glib::Propagation::Stop
-        } else {
-            glib::Propagation::Proceed
+    input_controller.connect_key_pressed(clone!(
+        #[weak] action_button,
+        #[strong] button_state,
+        #[upgrade_or] glib::Propagation::Proceed,
+        move |_, key, _, modifier| {
+            if key == gtk4::gdk::Key::Return && modifier.contains(gtk4::gdk::ModifierType::CONTROL_MASK) {
+                // Only trigger if in Send state (don't allow Ctrl+Enter to stop)
+                let current_state = {
+                    let state = button_state.lock().unwrap();
+                    state.clone()
+                };
+                
+                if current_state == ButtonState::Send {
+                    action_button.emit_clicked();
+                }
+                glib::Propagation::Stop
+            } else {
+                glib::Propagation::Proceed
+            }
         }
-    });
+    ));
     input_view.add_controller(input_controller);
 }
 
 fn send_message(
     message: String,
     model: String,
+    thinking_enabled: bool,
     chat_buffer: TextBuffer,
+    chat_scroll: ScrolledWindow,
     status_label: Label,
+    action_button: Button,
+    button_state: Arc<Mutex<ButtonState>>,
     app_state: AppState,
+    markdown_processor: Arc<MarkdownProcessor>
 ) {
     // Add user message to conversation
     {
@@ -238,39 +343,213 @@ fn send_message(
         });
     }
 
-    append_to_chat(&chat_buffer, "You", &message);
-    status_label.set_text("Sending message...");
-
-    let buffer_weak = chat_buffer.downgrade();
-    let status_weak = status_label.downgrade();
+    append_to_chat(&chat_buffer, "You", &message, &markdown_processor);
     
-    spawn_future_local(async move {
-        match api::send_chat_request(&app_state.ollama_url, &model, &app_state.conversation).await {
-            Ok(response_text) => {
-                // Add assistant response to conversation
-                {
-                    let mut conversation = app_state.conversation.lock().unwrap();
-                    conversation.push(ChatMessage {
-                        role: "assistant".to_string(),
-                        content: response_text.clone(),
-                    });
+    // Add placeholder for assistant message
+    let mut end_iter = chat_buffer.end_iter();
+    let assistant_prefix = if thinking_enabled {
+        "\n\nAssistant (thinking enabled):\n"
+    } else {
+        "\n\nAssistant:\n"
+    };
+    chat_buffer.insert(&mut end_iter, assistant_prefix);
+    
+    // Create mark where assistant response will be inserted
+    let assistant_start_mark = chat_buffer.create_mark(None, &chat_buffer.end_iter(), true);
+    
+    let status_text = if thinking_enabled {
+        "Assistant is thinking..."
+    } else {
+        "Assistant is typing..."
+    };
+    status_label.set_text(status_text);
+
+    // Create channels for streaming communication
+    let (stream_sender, stream_receiver) = async_channel::bounded::<String>(50);
+    let (result_sender, result_receiver) = async_channel::bounded::<Result<String, Box<dyn std::error::Error + Send + Sync>>>(1);
+    
+    // Spawn tokio task for API streaming
+    let app_state_clone = app_state.clone();
+    let model_clone = model.clone();
+    let task_handle = runtime().spawn(async move {
+        let result = api::send_chat_request_streaming(
+            &app_state_clone.ollama_url,
+            &model_clone,
+            &app_state_clone.conversation,
+            stream_sender,
+            thinking_enabled,
+        ).await;
+        let _ = result_sender.send(result).await;
+    });
+
+    // Store the handle for potential cancellation
+    {
+        let mut handle = app_state.current_request_handle.lock().unwrap();
+        *handle = Some(task_handle);
+    }   
+    
+    // Handle streaming updates on the main loop
+    spawn_future_local(clone!(
+        #[weak] chat_buffer,
+        #[weak] assistant_start_mark,
+        #[weak] chat_scroll,
+        async move {
+            let mut accumulated_text = String::new();
+            
+            while let Ok(token_batch) = stream_receiver.recv().await {
+                accumulated_text.push_str(&token_batch);
+                
+                // Update UI with accumulated text (plain text during streaming)
+                let mut start_iter = chat_buffer.iter_at_mark(&assistant_start_mark);
+                let mut end_iter = chat_buffer.end_iter();
+                
+                // Replace content from mark to end
+                chat_buffer.delete(&mut start_iter, &mut end_iter);
+                let mut insert_iter = chat_buffer.iter_at_mark(&assistant_start_mark);
+                chat_buffer.insert(&mut insert_iter, &accumulated_text);
+                
+                // Auto-scroll to bottom after each update
+                let adjustment = chat_scroll.vadjustment();
+                adjustment.set_value(adjustment.upper() - adjustment.page_size());
+            }
+        }
+    ));
+    
+    // Handle final result - apply markdown formatting when streaming completes
+    let app_state_final = app_state.clone();
+    spawn_future_local(clone!(
+        #[weak] status_label,
+        #[weak] chat_buffer,
+        #[weak] assistant_start_mark,
+        #[weak] action_button,
+        #[strong] button_state,
+        #[strong] markdown_processor,
+        async move {
+            if let Ok(result) = result_receiver.recv().await {
+                match result {
+                    Ok(response_text) => {
+                        // Clear the plain streaming text
+                        let mut start_iter = chat_buffer.iter_at_mark(&assistant_start_mark);
+                        let mut end_iter = chat_buffer.end_iter();
+                        chat_buffer.delete(&mut start_iter, &mut end_iter);
+                        
+                        // Insert formatted markdown text using the shared processor
+                        let mut insert_iter = chat_buffer.iter_at_mark(&assistant_start_mark);
+                        markdown_processor.insert_formatted_text(&chat_buffer, &response_text, &mut insert_iter);
+                        
+                        // Add complete response to conversation
+                        {
+                            let mut conversation = app_state_final.conversation.lock().unwrap();
+                            conversation.push(ChatMessage {
+                                role: "assistant".to_string(),
+                                content: response_text,
+                            });
+                        }
+                        
+                        status_label.set_text("Ready");
+                    }
+                    Err(e) => {
+                        status_label.set_text(&format!("Error: {}", e));
+                        
+                        // Show error in chat
+                        let mut start_iter = chat_buffer.iter_at_mark(&assistant_start_mark);
+                        let mut end_iter = chat_buffer.end_iter();
+                        chat_buffer.delete(&mut start_iter, &mut end_iter);
+                        let mut insert_iter = chat_buffer.iter_at_mark(&assistant_start_mark);
+                        chat_buffer.insert(&mut insert_iter, &format!("[Error: {}]", e));
+                    }
                 }
                 
-                if let (Some(chat_buffer), Some(status_label)) = (buffer_weak.upgrade(), status_weak.upgrade()) {
-                    append_to_chat(&chat_buffer, "Assistant", &response_text);
-                    status_label.set_text("Ready");
+                // Change button back to Send state when generation completes
+                {
+                    let mut state = button_state.lock().unwrap();
+                    *state = ButtonState::Send;
                 }
+                update_button_state(&action_button, ButtonState::Send);
             }
-            Err(e) => {
-                if let Some(status_label) = status_weak.upgrade() {
-                    status_label.set_text(&format!("Error: {}", e));
+        }
+    ));
+}
+
+// Helper functions 
+fn runtime() -> &'static Runtime {
+    static RUNTIME: OnceLock<Runtime> = OnceLock::new();
+    RUNTIME.get_or_init(|| {
+        Runtime::new().expect("Setting up tokio runtime needs to succeed.")
+    })
+}
+
+fn create_chat_view() -> (TextView, TextBuffer, Arc<MarkdownProcessor>) {
+    let chat_view = TextView::new();
+    chat_view.set_editable(false);
+    chat_view.set_cursor_visible(false);
+    chat_view.set_wrap_mode(WrapMode::WordChar);
+    chat_view.add_css_class("chat-text");
+    
+    let chat_buffer = TextBuffer::new(None);
+    chat_view.set_buffer(Some(&chat_buffer));
+    
+    // Set up markdown formatting tags
+    let markdown_processor = Arc::new(MarkdownProcessor::new());
+    markdown_processor.setup_tags(&chat_buffer);
+    
+    (chat_view, chat_buffer, markdown_processor)
+}
+
+fn load_models(model_list: StringList, dropdown: DropDown, status_label: Label, app_state: AppState) {
+    status_label.set_text("Loading models...");
+    
+    // Create communication channel
+    let (sender, receiver) = async_channel::bounded(1);
+    
+    // Spawn tokio task for API call
+    runtime().spawn(async move {
+        let result = api::fetch_models(&app_state.ollama_url).await;
+        let _ = sender.send(result).await;
+    });
+    
+    // Handle response on main loop
+    spawn_future_local(clone!(
+        #[weak] model_list,
+        #[weak] dropdown,
+        #[weak] status_label,
+        async move {
+            if let Ok(result) = receiver.recv().await {
+                match result {
+                    Ok(models) => {
+                        // Clear existing items and add new ones
+                        model_list.splice(0, model_list.n_items(), 
+                            &models.iter().map(|m| m.name.as_str()).collect::<Vec<_>>());
+                        
+                        // Select first model if available
+                        if model_list.n_items() > 0 && dropdown.selected() == gtk4::INVALID_LIST_POSITION {
+                            dropdown.set_selected(0);
+                        }
+                        
+                        status_label.set_text("Ready");
+                    }
+                    Err(e) => {
+                        status_label.set_text(&format!("Error loading models: {}", e));
+                    }
                 }
             }
         }
-    });
+    ));
 }
 
-fn append_to_chat(buffer: &TextBuffer, sender: &str, message: &str) {
+fn setup_thinking_checkbox_handler(thinking_checkbox: CheckButton, app_state: AppState) {
+    thinking_checkbox.connect_toggled(clone!(
+        #[strong] app_state,
+        move |checkbox| {
+            let is_active = checkbox.is_active();
+            if let Ok(mut thinking_enabled) = app_state.thinking_enabled.lock() {
+                *thinking_enabled = is_active;
+            }
+        }
+    ));
+}
+
+fn append_to_chat(buffer: &TextBuffer, sender: &str, message: &str, markdown_processor: &MarkdownProcessor) {
     let mut end_iter = buffer.end_iter();
     
     // Add spacing if buffer is not empty
@@ -279,6 +558,15 @@ fn append_to_chat(buffer: &TextBuffer, sender: &str, message: &str) {
         end_iter = buffer.end_iter();
     }
     
-    // Add sender label and message
-    buffer.insert(&mut end_iter, &format!("{}:\n{}", sender, message));
+    // Add sender label
+    buffer.insert(&mut end_iter, &format!("{}:\n", sender));
+    end_iter = buffer.end_iter();
+    
+    // Add message - user messages are always plain text
+    if sender == "You" {
+        buffer.insert(&mut end_iter, message);
+    } else {
+        // For assistant messages, use markdown formatting
+        markdown_processor.insert_formatted_text(buffer, message, &mut end_iter);
+    }
 }