Update app.py

app.py

@@ -8,6 +8,7 @@ import shutil
 import io
 from PIL import Image
 import fitz  # PyMuPDF
+import re
 
 # Set page configuration
 st.set_page_config(page_title="LaTeX Editor & Compiler", page_icon="📝", layout="wide")
@@ -85,6 +86,36 @@ def render_pdf_preview(pdf_data):
         st.error(f"Error rendering PDF preview: {str(e)}")
         return None
 
+# Extract partial command from cursor position
+def get_current_command(text, cursor_pos):
+    if cursor_pos <= 0:
+        return ""
+    
+    # Look for the last backslash before cursor
+    start_pos = text[:cursor_pos].rfind("\\")
+    if start_pos == -1:
+        return ""
+    
+    # Extract the partial command (from \ to cursor)
+    partial_cmd = text[start_pos:cursor_pos]
+    return partial_cmd
+
+# Find matching commands for autocomplete
+def find_matching_commands(partial_cmd, all_commands):
+    if not partial_cmd.startswith("\\"):
+        return []
+    
+    partial_without_backslash = partial_cmd[1:].lower()
+    matches = []
+    
+    for cmd in all_commands:
+        cmd_without_backslash = cmd[1:].lower()
+        # Check if command contains the partial input (without \)
+        if cmd_without_backslash.startswith(partial_without_backslash):
+            matches.append(cmd)
+    
+    return matches
+
 # LaTeX package reference
 latex_packages = {
     "Document": {
@@ -194,6 +225,11 @@ latex_commands = {
     }
 }
 
+# Create a flat list of all LaTeX commands for autocomplete
+all_latex_commands = []
+for category, commands in latex_commands.items():
+    all_latex_commands.extend(list(commands.keys()))
+
 # Default LaTeX template
 default_template = r"""\documentclass{article}
 \usepackage[utf8]{inputenc}
@@ -378,10 +414,31 @@ st.markdown("""
         background-color: #f8f9fa;
     }
     
-    /* PDF page image */
-    .pdf-page-image {
+    /* Autocomplete suggestions */
+    .autocomplete-container {
+        background-color: #f8f9fa;
         border: 1px solid #dee2e6;
-        margin-bottom: 15px;
+        border-radius: 4px;
+        padding: 10px;
+        margin-top: 10px;
+        max-height: 200px;
+        overflow-y: auto;
+    }
+    
+    .suggestion-item {
+        padding: 5px;
+        cursor: pointer;
+        border-radius: 3px;
+    }
+    
+    .suggestion-item:hover {
+        background-color: #e9ecef;
+    }
+    
+    /* Preview toggle button */
+    .preview-button {
+        margin-top: 15px;
+        width: 100%;
     }
 </style>
 """, unsafe_allow_html=True)
@@ -390,6 +447,14 @@ st.markdown("""
 def main():
     st.title("LaTeX Editor & PDF Compiler")
     
+    # Initialize session state variables
+    if 'latex_code' not in st.session_state:
+        st.session_state.latex_code = default_template
+    if 'cursor_pos' not in st.session_state:
+        st.session_state.cursor_pos = 0
+    if 'show_preview' not in st.session_state:
+        st.session_state.show_preview = False
+    
     # Display installation status
     if not is_pdflatex_installed():
         st.warning("⚠️ LaTeX is not installed correctly. The PDF compilation feature will not work.")
@@ -406,25 +471,57 @@ python3-dev
 python3-pip
 poppler-utils""", language="text")
     
-    # Create layout with sidebar
+    # Create layout
     col1, col2 = st.columns([3, 2])
     
     with col1:
         st.subheader("LaTeX Editor")
         
-        # Initialize session state
-        if 'latex_code' not in st.session_state:
-            st.session_state.latex_code = default_template
+        # Detect current command for autocomplete
+        if 'last_input' in st.session_state:
+            current_command = get_current_command(st.session_state.latex_code, st.session_state.cursor_pos)
+            matching_commands = find_matching_commands(current_command, all_latex_commands)
+            
+            # Display autocomplete suggestions when typing a command
+            if current_command and matching_commands:
+                st.markdown("### Command Suggestions")
+                st.markdown('<div class="autocomplete-container">', unsafe_allow_html=True)
+                for cmd in matching_commands[:10]:  # Limit to 10 suggestions
+                    if st.button(cmd, key=f"suggest_{cmd}"):
+                        # Replace partial command with the full command
+                        text_before = st.session_state.latex_code[:st.session_state.cursor_pos - len(current_command)]
+                        text_after = st.session_state.latex_code[st.session_state.cursor_pos:]
+                        st.session_state.latex_code = text_before + cmd + text_after
+                        st.rerun()
+                st.markdown('</div>', unsafe_allow_html=True)
         
         # LaTeX editor
         latex_code = st.text_area(
             "Edit your LaTeX document:",
             value=st.session_state.latex_code,
             height=500,
-            key="latex_editor"
+            key="latex_editor",
+            on_change=lambda: setattr(st.session_state, 'last_input', True)
         )
         st.session_state.latex_code = latex_code
         
+        # Get cursor position for autocomplete (using JS - note this is limited in Streamlit)
+        # This is a workaround since Streamlit doesn't directly expose cursor position
+        st.markdown("""
+        <script>
+        document.addEventListener('DOMContentLoaded', function() {
+            const textArea = document.querySelector('textarea');
+            if (textArea) {
+                textArea.addEventListener('keyup', function(e) {
+                    const cursorPos = this.selectionStart;
+                    // Would need a way to communicate this to Python
+                    console.log("Cursor position:", cursorPos);
+                });
+            }
+        });
+        </script>
+        """, unsafe_allow_html=True)
+        
         # Control buttons
         col1_1, col1_2, col1_3 = st.columns(3)
         
@@ -443,9 +540,9 @@ poppler-utils""", language="text")
                 st.rerun()
     
     with col2:
-        st.subheader("PDF Preview")
+        st.subheader("PDF Output")
         
-        # PDF compilation and preview
+        # PDF compilation
         if 'compile_clicked' in st.session_state and st.session_state.compile_clicked:
             with st.spinner("Compiling LaTeX to PDF..."):
                 pdf_data, stdout, stderr = latex_to_pdf(latex_code)
@@ -454,17 +551,22 @@ poppler-utils""", language="text")
                     st.session_state.pdf_data = pdf_data
                     st.success("PDF compiled successfully!")
                     
-                    # Render preview
-                    preview_images = render_pdf_preview(pdf_data)
-                    if preview_images:
-                        st.write("PDF Preview (First Pages):")
-                        for i, img in enumerate(preview_images):
-                            st.image(img, caption=f"Page {i+1}", use_column_width=True, 
-                                    clamp=True, output_format="PNG")
+                    # Toggle button for preview
+                    if st.button("Show/Hide Preview", use_container_width=True):
+                        st.session_state.show_preview = not st.session_state.show_preview
                     
-                    # Download button
+                    # Download button always available
                     st.markdown(get_download_link(pdf_data), unsafe_allow_html=True)
                     
+                    # Optional preview
+                    if st.session_state.show_preview:
+                        preview_images = render_pdf_preview(pdf_data)
+                        if preview_images:
+                            st.write("PDF Preview (First Pages):")
+                            for i, img in enumerate(preview_images):
+                                st.image(img, caption=f"Page {i+1}", use_container_width=True, 
+                                        output_format="PNG")
+                    
                     st.session_state.compile_clicked = False
                 else:
                     st.error("Compilation Error")
@@ -475,71 +577,54 @@ poppler-utils""", language="text")
         
         # Display previous PDF if available
         elif 'pdf_data' in st.session_state and st.session_state.pdf_data:
-            preview_images = render_pdf_preview(st.session_state.pdf_data)
-            if preview_images:
-                st.write("PDF Preview (First Pages):")
-                for i, img in enumerate(preview_images):
-                    st.image(img, caption=f"Page {i+1}", use_column_width=True, 
-                            clamp=True, output_format="PNG")
+            # Toggle button for preview
+            if st.button("Show/Hide Preview", use_container_width=True):
+                st.session_state.show_preview = not st.session_state.show_preview
             
-            # Download button
+            # Download button always available
             st.markdown(get_download_link(st.session_state.pdf_data), unsafe_allow_html=True)
+            
+            # Optional preview
+            if st.session_state.show_preview:
+                preview_images = render_pdf_preview(st.session_state.pdf_data)
+                if preview_images:
+                    st.write("PDF Preview (First Pages):")
+                    for i, img in enumerate(preview_images):
+                        st.image(img, caption=f"Page {i+1}", use_container_width=True, 
+                                output_format="PNG")
         else:
-            st.info("Compile your LaTeX document to see the PDF preview")
+            st.info("Compile your LaTeX document to generate a PDF for download")
     
     # LaTeX Reference Sidebar
     st.sidebar.title("LaTeX Reference")
     
-    # Search functionality
-    search_query = st.sidebar.text_input("Search commands or packages", "")
+    # Command quick search
+    quick_search = st.sidebar.text_input("Type to find commands (e.g. 'fr' for '\\frac')")
     
-    if search_query:
-        st.sidebar.subheader("Search Results")
-        found = False
-        
-        # Search commands
+    if quick_search:
+        # Find and display matching commands
+        matching_cmds = []
         for category, commands in latex_commands.items():
-            filtered_commands = {cmd: desc for cmd, desc in commands.items() 
-                             if search_query.lower() in cmd.lower() or search_query.lower() in desc.lower()}
-            
-            if filtered_commands:
-                found = True
-                with st.sidebar.expander(f"{category} ({len(filtered_commands)} results)"):
-                    st.markdown('<div class="command-list">', unsafe_allow_html=True)
-                    for cmd, desc in filtered_commands.items():
-                        col1, col2 = st.columns([3, 1])
-                        with col1:
-                            st.markdown(f'<div><span class="latex-command">{cmd}</span> <span class="command-description">{desc}</span></div>', unsafe_allow_html=True)
-                        with col2:
-                            if st.button("Insert", key=f"btn_{cmd}", help=f"Insert {cmd} into editor"):
-                                st.session_state.latex_code += f"\n{cmd}"
-                                st.rerun()
-                    st.markdown('</div>', unsafe_allow_html=True)
-        
-        # Search packages
-        for category, packages in latex_packages.items():
-            filtered_packages = {pkg: desc for pkg, desc in packages.items() 
-                              if search_query.lower() in pkg.lower() or search_query.lower() in desc.lower()}
-            
-            if filtered_packages:
-                found = True
-                with st.sidebar.expander(f"Packages: {category} ({len(filtered_packages)} results)"):
-                    st.markdown('<div class="command-list">', unsafe_allow_html=True)
-                    for pkg, desc in filtered_packages.items():
-                        col1, col2 = st.columns([3, 1])
-                        with col1:
-                            st.markdown(f'<div><span class="latex-command">{pkg}</span> <span class="command-description">{desc}</span></div>', unsafe_allow_html=True)
-                        with col2:
-                            if st.button("Insert", key=f"btn_{pkg}", help=f"Insert {pkg} into editor"):
-                                st.session_state.latex_code += f"\n{pkg}"
-                                st.rerun()
-                    st.markdown('</div>', unsafe_allow_html=True)
+            for cmd, desc in commands.items():
+                cmd_without_backslash = cmd.replace("\\", "").lower()
+                if quick_search.lower() in cmd_without_backslash:
+                    matching_cmds.append((cmd, desc, category))
         
-        if not found:
-            st.sidebar.info("No matching commands or packages found")
+        if matching_cmds:
+            st.sidebar.markdown("### Matching Commands")
+            for cmd, desc, category in matching_cmds[:15]:  # Limit to 15 results
+                col1, col2 = st.sidebar.columns([4, 1])
+                with col1:
+                    st.markdown(f"<div><span class='latex-command'>{cmd}</span> <small>{category}</small></div>", unsafe_allow_html=True)
+                with col2:
+                    if st.button("Insert", key=f"quick_{cmd}"):
+                        st.session_state.latex_code += f"\n{cmd}"
+                        st.rerun()
+        else:
+            st.sidebar.info("No matching commands found")
     
-    else:
-        # Display full reference when not searching
+    # Regular categories
+    if not quick_search:
         tab1, tab2 = st.sidebar.tabs(["Commands", "Packages"])
         
         with tab1:
@@ -547,11 +632,11 @@ poppler-utils""", language="text")
                 with st.expander(category, expanded=category=="Math"):
                     st.markdown('<div class="command-list">', unsafe_allow_html=True)
                     for cmd, desc in commands.items():
-                        col1, col2 = st.columns([3, 1])
+                        col1, col2 = st.sidebar.columns([4, 1])
                         with col1:
-                            st.markdown(f'<div><span class="latex-command">{cmd}</span> <span class="command-description">{desc}</span></div>', unsafe_allow_html=True)
+                            st.markdown(f"<div><span class='latex-command'>{cmd}</span></div>", unsafe_allow_html=True)
                         with col2:
-                            if st.button("Insert", key=f"btn_{cmd}", help=f"Insert {cmd} into editor"):
+                            if st.button("Insert", key=f"btn_{cmd}"):
                                 st.session_state.latex_code += f"\n{cmd}"
                                 st.rerun()
                     st.markdown('</div>', unsafe_allow_html=True)
@@ -561,11 +646,11 @@ poppler-utils""", language="text")
                 with st.expander(category):
                     st.markdown('<div class="command-list">', unsafe_allow_html=True)
                     for pkg, desc in packages.items():
-                        col1, col2 = st.columns([3, 1])
+                        col1, col2 = st.sidebar.columns([4, 1])
                         with col1:
-                            st.markdown(f'<div><span class="latex-command">{pkg}</span> <span class="command-description">{desc}</span></div>', unsafe_allow_html=True)
+                            st.markdown(f"<div><span class='latex-command'>{pkg}</span></div>", unsafe_allow_html=True)
                         with col2:
-                            if st.button("Insert", key=f"btn_{pkg}", help=f"Insert {pkg} into editor"):
+                            if st.button("Insert", key=f"btn_{pkg}"):
                                 st.session_state.latex_code += f"\n{pkg}"
                                 st.rerun()
                     st.markdown('</div>', unsafe_allow_html=True)