src-tauri/src/commands.rs

@@ -166,6 +166,101 @@ pub fn open_log_dir(app: AppHandle) -> Result<(), String> {
     Ok(())
 }
 
+#[derive(Debug, Serialize, Deserialize, Clone)]
+pub struct Ti2Metadata {
+    pub basename: String,
+    pub cwd: String,
+    pub instrument: Option<String>,
+    pub patch_count: Option<u32>,
+    pub colorant_count: Option<u32>,
+    pub pages: Option<u32>,
+    pub has_ti1: bool,
+    pub has_ti2: bool,
+}
+
+#[tauri::command]
+pub fn parse_ti2_header(app: AppHandle, file_path: String) -> Result<Ti2Metadata, String> {
+    let path = std::path::PathBuf::from(&file_path);
+    if !path.exists() {
+        return Err(format!("File does not exist: {}", file_path));
+    }
+
+    let content = std::fs::read_to_string(&path)
+        .map_err(|e| format!("Failed to read target file: {}", e))?;
+
+    let parent = path.parent().unwrap_or_else(|| std::path::Path::new(""));
+    let file_stem = path.file_stem().and_then(|s| s.to_str()).unwrap_or("");
+    let cwd = parent.to_string_lossy().to_string();
+    let basename = file_stem.to_string();
+
+    let ti1_path = parent.join(format!("{}.ti1", basename));
+    let ti2_path = parent.join(format!("{}.ti2", basename));
+
+    let mut instrument: Option<String> = None;
+    let mut patch_count: Option<u32> = None;
+    let mut colorant_count: Option<u32> = None;
+    let mut pages: Option<u32> = None;
+
+    for line in content.lines() {
+        let trimmed = line.trim();
+        if trimmed.starts_with("TARGET_INSTRUMENT") {
+            let parts: Vec<&str> = trimmed.split_whitespace().collect();
+            if parts.len() >= 2 {
+                instrument = Some(parts[1].trim_matches('"').to_string());
+            }
+        } else if trimmed.starts_with("NUMBER_OF_FIELDS") {
+            let parts: Vec<&str> = trimmed.split_whitespace().collect();
+            if parts.len() >= 2 {
+                colorant_count = parts[1].parse::<u32>().ok();
+            }
+        } else if trimmed.starts_with("NUMBER_OF_SETS") {
+            let parts: Vec<&str> = trimmed.split_whitespace().collect();
+            if parts.len() >= 2 {
+                patch_count = parts[1].parse::<u32>().ok();
+            }
+        } else if trimmed.starts_with("NUMBER_OF_PAGES") || trimmed.starts_with("PAGES") {
+            let parts: Vec<&str> = trimmed.split_whitespace().collect();
+            if parts.len() >= 2 {
+                pages = parts[1].parse::<u32>().ok();
+            }
+        }
+    }
+
+    Ok(Ti2Metadata {
+        basename,
+        cwd,
+        instrument,
+        patch_count,
+        colorant_count,
+        pages,
+        has_ti1: ti1_path.exists(),
+        has_ti2: ti2_path.exists(),
+    })
+}
+
+#[tauri::command]
+pub async fn select_existing_target(
+    app: AppHandle,
+    default_dir: Option<String>,
+) -> Result<Option<String>, String> {
+    use tauri_plugin_dialog::DialogExt;
+
+    let mut builder = app.dialog().file().add_filter("ArgyllCMS Target Files (.ti1, .ti2)", &["ti1", "ti2"]);
+    if let Some(ref dir) = default_dir {
+        if !dir.trim().is_empty() {
+            builder = builder.set_directory(std::path::PathBuf::from(dir));
+        }
+    }
+
+    let (tx, rx) = tokio::sync::oneshot::channel();
+    builder.pick_file(move |file_path| {
+        let res = file_path.map(|p| p.to_string());
+        let _ = tx.send(res);
+    });
+
+    rx.await.map_err(|e| format!("Dialog channel error: {}", e))
+}
+
 #[tauri::command]
 pub async fn select_target_file(
     app: AppHandle,

src-tauri/src/lib.rs

@@ -33,6 +33,8 @@ pub fn run() {
             commands::get_default_working_dir,
             commands::get_log_path,
             commands::open_log_dir,
+            commands::parse_ti2_header,
+            commands::select_existing_target,
             commands::select_target_file,
             commands::select_directory,
             commands::send_stdin,

src/index.html

@@ -97,7 +97,10 @@
             </div>
 
             <div class="form-group">
-              <label>Project Directory & Filename</label>
+              <div style="display: flex; justify-content: space-between; align-items: center; margin-bottom: 6px;">
+                <label style="margin: 0;">Project Directory &amp; Filename</label>
+                <button type="button" id="btnOpenExisting" class="secondary" style="font-size: 0.75rem; padding: 2px 8px;" title="Open existing .ti1 or .ti2 target file">📂 Open Target...</button>
+              </div>
               <div class="input-row has-btn">
                 <input type="text" id="targetBasename" placeholder="e.g. my_paper_profile">
                 <button type="button" id="btnBrowse" class="secondary">Browse...</button>
@@ -305,6 +308,15 @@
           <h2>Measure Target</h2>
           <p>Read the printed target patches with your spectrophotometer.</p>
 
+          <!-- Loaded Target Context Banner -->
+          <div id="stage3LoadedTargetBanner" class="info-banner hidden" style="margin-bottom: 16px; background: rgba(59, 130, 246, 0.1); border: 1px solid rgba(59, 130, 246, 0.3); padding: 10px 14px; border-radius: 6px; display: flex; justify-content: space-between; align-items: center;">
+            <div>
+              <strong>Active Target:</strong> <span id="stage3TargetBasename" style="font-family: monospace; font-weight: 600;"></span>
+              <div id="stage3TargetMeta" style="font-size: 0.8rem; opacity: 0.8; margin-top: 2px;"></div>
+            </div>
+            <span class="badge" id="stage3TargetBadge" style="background: var(--accent-color, #3b82f6); color: white; padding: 3px 8px; border-radius: 4px; font-size: 0.75rem; font-weight: 500;">Ready</span>
+          </div>
+
           <!-- Instrument & Hardware Port Selector -->
           <div class="form-container" style="margin-bottom: 16px;">
             <div class="form-group">

src/js/chartread.js

@@ -9,12 +9,38 @@ let stage2Basename = "";
 let stage2Cwd = "";
 
 /**
- * Called by printtarg.js after Stage 2 completes.
+ * Called by printtarg.js after Stage 2 completes, or when resuming from .ti2.
  */
 export function setStage2Result(basename, cwd) {
   stage2Basename = basename || wizardState.basename;
   stage2Cwd = cwd || wizardState.cwd;
   wizardState.setTarget(stage2Basename, stage2Cwd);
+  populateStage3TargetContext();
+}
+
+export function populateStage3TargetContext(metadata) {
+  const banner = document.getElementById("stage3LoadedTargetBanner");
+  const basenameEl = document.getElementById("stage3TargetBasename");
+  const metaEl = document.getElementById("stage3TargetMeta");
+  const badgeEl = document.getElementById("stage3TargetBadge");
+
+  const basename = (metadata && metadata.basename) || stage2Basename || wizardState.basename;
+  const cwd = (metadata && metadata.cwd) || stage2Cwd || wizardState.cwd;
+
+  if (basename && banner) {
+    banner.classList.remove("hidden");
+    if (basenameEl) basenameEl.textContent = `${basename}.ti2`;
+    if (metaEl) {
+      const parts = [];
+      if (metadata && metadata.patch_count) parts.push(`${metadata.patch_count} patches`);
+      if (metadata && metadata.instrument) parts.push(`Instrument: ${metadata.instrument}`);
+      if (cwd) parts.push(`Dir: ${cwd}`);
+      metaEl.textContent = parts.join(" • ");
+    }
+    if (badgeEl) {
+      badgeEl.textContent = metadata ? "Resumed from .ti2" : "Generated";
+    }
+  }
 }
 
 // State machine states

src/js/state.js

@@ -8,7 +8,32 @@ export const wizardState = {
   setTarget(basename, cwd) {
     if (basename) this.basename = basename;
     if (cwd) this.cwd = cwd;
-    this.updateGating();
+    return this.updateGating();
+  },
+
+  navigateToStage(stageNumber) {
+    this.currentStage = stageNumber;
+    const steps = document.querySelectorAll('.step');
+    const stages = document.querySelectorAll('.stage');
+
+    steps.forEach(s => {
+      if (s.getAttribute('data-step') === String(stageNumber)) {
+        s.classList.remove('disabled');
+        s.classList.add('active');
+      } else {
+        s.classList.remove('active');
+      }
+    });
+
+    stages.forEach(s => {
+      if (s.id === `stage-${stageNumber}`) {
+        s.classList.remove('hidden');
+        s.classList.add('active');
+      } else {
+        s.classList.remove('active');
+        s.classList.add('hidden');
+      }
+    });
   },
 
   async updateGating() {

src/js/targen.js

@@ -1,6 +1,7 @@
 const { invoke } = window.__TAURI__.core;
 const { listen } = window.__TAURI__.event;
 import { setStage1Result } from './printtarg.js';
+import { populateStage3TargetContext } from './chartread.js';
 import { wizardState } from './state.js';
 
 export function initTargen() {
@@ -12,6 +13,7 @@ export function initTargen() {
   const targetBasename = document.getElementById("targetBasename");
   const selectedPathDisplay = document.getElementById("selectedPathDisplay");
   const btnBrowse = document.getElementById("btnBrowse");
+  const btnOpenExisting = document.getElementById("btnOpenExisting");
   const btnGenerate = document.getElementById("btnGenerate");
   const logContainer = document.getElementById("targenLogContainer");
   const logPre = document.getElementById("targenLog");
@@ -100,13 +102,64 @@ export function initTargen() {
           }
           updateGenerateButton();
         }
-      } catch (err)
- {
+      } catch (err) {
         console.error("Failed to open file dialog:", err);
       }
     });
   }
 
+  // Open existing target (.ti1 or .ti2)
+  if (btnOpenExisting) {
+    btnOpenExisting.addEventListener("click", async () => {
+      try {
+        const filePath = await invoke("select_existing_target", {
+          defaultDir: currentWorkingDir || null,
+        });
+
+        if (filePath) {
+          const isWindows = filePath.includes('\\');
+          const sep = isWindows ? '\\' : '/';
+          const parts = filePath.split(sep);
+          const fileName = parts.pop();
+          const isTi2 = fileName.toLowerCase().endsWith('.ti2');
+
+          currentWorkingDir = parts.join(sep);
+          const basename = fileName.replace(/\.(ti1|ti2)$/i, '');
+
+          if (targetBasename) {
+            targetBasename.value = basename;
+          }
+          if (selectedPathDisplay) {
+            selectedPathDisplay.textContent = `Directory: ${currentWorkingDir}`;
+          }
+          updateGenerateButton();
+
+          if (isTi2) {
+            // Parse .ti2 metadata and jump straight to Stage 3
+            try {
+              const meta = await invoke("parse_ti2_header", { filePath });
+              await wizardState.setTarget(meta.basename, meta.cwd);
+              populateStage3TargetContext(meta);
+              wizardState.navigateToStage(3);
+            } catch (parseErr) {
+              console.warn("Could not parse .ti2 header, navigating with basic target:", parseErr);
+              await wizardState.setTarget(basename, currentWorkingDir);
+              populateStage3TargetContext({ basename, cwd: currentWorkingDir });
+              wizardState.navigateToStage(3);
+            }
+          } else {
+            // .ti1 selected -> advance to Stage 2 (Print Layout)
+            await wizardState.setTarget(basename, currentWorkingDir);
+            setStage1Result(basename, currentWorkingDir);
+            wizardState.navigateToStage(2);
+          }
+        }
+      } catch (err) {
+        console.error("Failed to open existing target:", err);
+      }
+    });
+  }
+
   // Generate button clicks
   if (btnGenerate) {
     btnGenerate.addEventListener("click", async () => {