Merge a540edd437 into 4dd73a211a

.github/workflows/ci.yml

@@ -1,22 +1,27 @@
-name: CI (build)
-
-on:
+name: CI
+'on':
   push:
     branches: [master]
   pull_request:
 
 permissions:
   contents: read
+  pull-requests: write
 
 jobs:
+  label:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/labeler@v5
+
   clang-format:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
         with:
           submodules: recursive
 
-      - uses: actions/setup-python@v5
+      - uses: actions/setup-python@v6
         with:
           python-version: '3.14'
 
@@ -29,18 +34,16 @@ jobs:
           sudo apt-get install -y clang-format-21
 
       - name: Run clang-format
-        run: |
-          PATH="/usr/lib/llvm-21/bin:$PATH" ./bin/clang-format-fix
-          git diff --exit-code || (echo "Please run 'bin/clang-format-fix' to fix formatting issues" && exit 1)
+        run: PATH="/usr/lib/llvm-21/bin:$PATH" ./bin/clang-format-fix && git diff --exit-code || (echo "Please run 'bin/clang-format-fix' to fix formatting issues" && exit 1)
 
   cppcheck:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
         with:
           submodules: recursive
 
-      - uses: actions/setup-python@v5
+      - uses: actions/setup-python@v6
         with:
           python-version: '3.14'
 
@@ -53,11 +56,11 @@ jobs:
   build:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
         with:
           submodules: recursive
 
-      - uses: actions/setup-python@v5
+      - uses: actions/setup-python@v6
         with:
           python-version: '3.14'
 
@@ -87,18 +90,62 @@ jobs:
             if [ -n "$flash_line" ]; then echo "- ${flash_line}"; else echo "- Flash: not found"; fi
           } >> "$GITHUB_STEP_SUMMARY"
 
-      # Upload both the binary and the stats/log so Stage 2 can read them without checkout.
       - name: Upload firmware.bin artifact
         uses: actions/upload-artifact@v4
         with:
-          name: firmware-bin
+          name: ${{ github.event_name == 'pull_request' && format('firmware-bin-pr-{0}-{1}', github.event.pull_request.number, steps.short_sha.outputs.short) || format('firmware-bin-{0}', steps.short_sha.outputs.short) }}
           path: .pio/build/default/firmware.bin
           if-no-files-found: error
 
-      - name: Upload build metadata artifact
-        uses: actions/upload-artifact@v4
+      - name: Comment PR with firmware stats and firmware.bin
+        if: github.event_name == 'pull_request'
+        uses: actions/github-script@v7
         with:
-          name: build-meta
-          path: |
-            pio.log
-          if-no-files-found: error
+          script: |
+            const marker = '<!-- firmware-stats -->';
+            const ram = `${{ steps.fw_stats.outputs.ram_line }}`.trim();
+            const flash = `${{ steps.fw_stats.outputs.flash_line }}`.trim();
+            const prNumber = context.payload.pull_request?.number;
+            const shortSha = `${{ steps.short_sha.outputs.short }}`.trim() || context.sha.substring(0, 7);
+            const artifactName = prNumber
+              ? `firmware-bin-pr-${prNumber}-${shortSha}`
+              : `firmware-bin-${shortSha}`;
+            let firmwareLine = 'Firmware: artifact not found';
+            try {
+              const { data: artifacts } = await github.rest.actions.listWorkflowRunArtifacts({
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+                run_id: context.runId,
+              });
+              const firmwareArtifact = artifacts.artifacts.find((artifact) => artifact.name === artifactName);
+              if (firmwareArtifact) {
+                const artifactUiUrl = `https://github.com/${context.repo.owner}/${context.repo.repo}/actions/runs/${context.runId}/artifacts/${firmwareArtifact.id}`;
+                firmwareLine = `Firmware: [${artifactName}](${artifactUiUrl})`;
+              } else {
+                firmwareLine = `Firmware: artifact not found (${artifactName})`;
+              }
+            } catch (error) {
+              firmwareLine = `Firmware: artifact lookup failed (${error.message})`;
+            }
+            const body = `${marker}\n**Firmware build stats**\n\n\`\`\`\n${ram || 'RAM: not found'}\n${flash || 'Flash: not found'}\n\`\`\`\n\n**Firmware binary**\n${firmwareLine}`;
+            const { data: comments } = await github.rest.issues.listComments({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              issue_number: context.issue.number,
+            });
+            const existing = comments.find((comment) => comment.body && comment.body.includes(marker));
+            if (existing) {
+              await github.rest.issues.updateComment({
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+                comment_id: existing.id,
+                body,
+              });
+            } else {
+              await github.rest.issues.createComment({
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+                issue_number: context.issue.number,
+                body,
+              });
+            }

.github/workflows/pr-formatting-check.yml

@@ -37,10 +37,10 @@ jobs:
               `${{ steps.title_check.outputs.error_message || steps.title_check.outputs.error || '' }}`.trim();
             const details = error ? `\n\n**Error:** ${error}` : '\n\n**Error:** See workflow logs.';
             const body = `${marker}
-**PR title check failed**
+            **PR title check failed**
 
-Please use a Conventional Commit-style prefix (e.g., \`feat:\`, \`fix:\`, \`docs:\`, \`chore:\`).
-If this change should appear in release notes, ensure the title reflects the correct category.${details}`;
+            Please use a Conventional Commit-style prefix (e.g., \`feat:\`, \`fix:\`, \`docs:\`, \`chore:\`).
+            If this change should appear in release notes, ensure the title reflects the correct category.${details}`;
 
             const { data: comments } = await github.rest.issues.listComments({
               owner: context.repo.owner,

.github/workflows/pr-writer.yml

@@ -1,145 +0,0 @@
-comment_firmware:
-  runs-on: ubuntu-latest
-  steps:
-    - name: Find the matching CI run for this PR SHA
-      id: find_run
-      uses: actions/github-script@v8
-      with:
-        script: |
-          const owner = context.repo.owner;
-          const repo = context.repo.repo;
-          const pr = context.payload.pull_request;
-          const headSha = pr.head.sha;
-
-          const { data } = await github.rest.actions.listWorkflowRunsForRepo({
-            owner,
-            repo,
-            event: "pull_request",
-            per_page: 50,
-          });
-
-          const run = data.workflow_runs.find(r => r.head_sha === headSha && r.name === "CI (build)");
-          if (!run) core.setFailed(`No matching CI (build) run found for head_sha=${headSha}.`);
-
-          core.setOutput("run_id", String(run.id));
-          core.setOutput("run_html_url", run.html_url);
-
-    - name: Locate artifact IDs in the CI run
-      id: artifacts
-      uses: actions/github-script@v8
-      with:
-        script: |
-          const owner = context.repo.owner;
-          const repo = context.repo.repo;
-          const runId = Number("${{ steps.find_run.outputs.run_id }}");
-
-          const { data } = await github.rest.actions.listWorkflowRunArtifacts({
-            owner,
-            repo,
-            run_id: runId,
-            per_page: 100,
-          });
-
-          const artifacts = data.artifacts || [];
-          const fw = artifacts.find(a => a.name === "firmware-bin");
-          const meta = artifacts.find(a => a.name === "build-meta");
-
-          if (!meta) core.setFailed("build-meta artifact not found in CI run artifacts.");
-          // firmware-bin is nice-to-have for linking; fail if you want.
-          core.setOutput("fw_id", fw ? String(fw.id) : "");
-          core.setOutput("meta_id", String(meta.id));
-
-    - name: Download build-meta artifact zip and extract pio.log
-      id: parse_log
-      shell: bash
-      env:
-        OWNER: ${{ github.repository_owner }}
-        REPO: ${{ github.event.repository.name }}
-        META_ID: ${{ steps.artifacts.outputs.meta_id }}
-        GH_TOKEN: ${{ github.token }}
-      run: |
-        set -euo pipefail
-
-        # Download artifact zip via GitHub API (will redirect to blob storage; -L follows)
-        api="https://api.github.com/repos/${OWNER}/${REPO}/actions/artifacts/${META_ID}/zip"
-        curl -sSL \
-          -H "Authorization: Bearer ${GH_TOKEN}" \
-          -H "X-GitHub-Api-Version: 2022-11-28" \
-          -o build-meta.zip \
-          "${api}"
-
-        mkdir -p build-meta
-        unzip -q build-meta.zip -d build-meta
-
-        if [[ ! -f build-meta/pio.log ]]; then
-          echo "pio.log not found inside build-meta artifact"
-          echo "ram_line=" >> "$GITHUB_OUTPUT"
-          echo "flash_line=" >> "$GITHUB_OUTPUT"
-          exit 0
-        fi
-
-        ram_line="$(grep -E "RAM:\s" -m1 build-meta/pio.log || true)"
-        flash_line="$(grep -E "Flash:\s" -m1 build-meta/pio.log || true)"
-
-        echo "ram_line=${ram_line}" >> "$GITHUB_OUTPUT"
-        echo "flash_line=${flash_line}" >> "$GITHUB_OUTPUT"
-
-    - name: Post/update PR comment with RAM/Flash + artifact links
-      uses: actions/github-script@v8
-      with:
-        script: |
-          const owner = context.repo.owner;
-          const repo = context.repo.repo;
-          const prNumber = context.payload.pull_request.number;
-
-          const runId = Number("${{ steps.find_run.outputs.run_id }}");
-          const runUrl = "${{ steps.find_run.outputs.run_html_url }}";
-
-          const marker = '<!-- firmware-stats -->';
-          const ram = `${{ steps.parse_log.outputs.ram_line }}`.trim();
-          const flash = `${{ steps.parse_log.outputs.flash_line }}`.trim();
-
-          const fwId = `${{ steps.artifacts.outputs.fw_id }}`.trim();
-          const metaId = `${{ steps.artifacts.outputs.meta_id }}`.trim();
-
-          const fwUrl = fwId ? `https://github.com/${owner}/${repo}/actions/runs/${runId}/artifacts/${fwId}` : null;
-          const metaUrl = metaId ? `https://github.com/${owner}/${repo}/actions/runs/${runId}/artifacts/${metaId}` : null;
-
-          const body =
-`${marker}
-**Firmware build stats**
-
-\`\`\`
-${ram || "RAM: not found"}
-${flash || "Flash: not found"}
-\`\`\`
-
-**Artifacts**
-- CI run: ${runUrl}
-- Firmware binary: ${fwUrl ? `[firmware-bin](${fwUrl})` : "artifact not found"}
-- Build logs: ${metaUrl ? `[build-meta](${metaUrl})` : "artifact not found"}
-`;
-
-          const { data: comments } = await github.rest.issues.listComments({
-            owner,
-            repo,
-            issue_number: prNumber,
-            per_page: 100,
-          });
-
-          const existing = comments.find(c => (c.body || "").includes(marker));
-          if (existing) {
-            await github.rest.issues.updateComment({
-              owner,
-              repo,
-              comment_id: existing.id,
-              body,
-            });
-          } else {
-            await github.rest.issues.createComment({
-              owner,
-              repo,
-              issue_number: prNumber,
-              body,
-            });
-          }

README.md

@@ -95,20 +95,6 @@ Connect your Xteink X4 to your computer via USB-C and run the following command.
 ```sh
 pio run --target upload
 ```
-### Debugging
-
-After flashing the new features, it’s recommended to capture detailed logs from the serial port.
-
-First, make sure all required Python packages are installed:
-
-```python
-python3 -m pip install serial colorama matplotlib
-```
-after that run the script:
-```sh
-python3 scripts/debugging_monitor.py
-```
-This was tested on Debian and should work on most Linux systems. Minor adjustments may be required for Windows or macOS.
 
 ## Internals
 

lib/GfxRenderer/GfxRenderer.cpp

@@ -415,21 +415,13 @@ void GfxRenderer::displayBuffer(const HalDisplay::RefreshMode refreshMode) const
 
 std::string GfxRenderer::truncatedText(const int fontId, const char* text, const int maxWidth,
                                        const EpdFontFamily::Style style) const {
-  if (!text || maxWidth <= 0) return "";
-
   std::string item = text;
-  const char* ellipsis = "...";
-  int textWidth = getTextWidth(fontId, item.c_str(), style);
-  if (textWidth <= maxWidth) {
-    // Text fits, return as is
-    return item;
+  int itemWidth = getTextWidth(fontId, item.c_str(), style);
+  while (itemWidth > maxWidth && item.length() > 8) {
+    item.replace(item.length() - 5, 5, "...");
+    itemWidth = getTextWidth(fontId, item.c_str(), style);
   }
-
-  while (!item.empty() && getTextWidth(fontId, (item + ellipsis).c_str(), style) >= maxWidth) {
-    utf8RemoveLastChar(item);
-  }
-
-  return item.empty() ? ellipsis : item + ellipsis;
+  return item;
 }
 
 // Note: Internal driver treats screen in command orientation; this library exposes a logical orientation

lib/Utf8/Utf8.cpp

@@ -29,20 +29,3 @@ uint32_t utf8NextCodepoint(const unsigned char** string) {
 
   return cp;
 }
-
-size_t utf8RemoveLastChar(std::string& str) {
-  if (str.empty()) return 0;
-  size_t pos = str.size() - 1;
-  while (pos > 0 && (static_cast<unsigned char>(str[pos]) & 0xC0) == 0x80) {
-    --pos;
-  }
-  str.resize(pos);
-  return pos;
-}
-
-// Truncate string by removing N UTF-8 characters from the end
-void utf8TruncateChars(std::string& str, const size_t numChars) {
-  for (size_t i = 0; i < numChars && !str.empty(); ++i) {
-    utf8RemoveLastChar(str);
-  }
-}

lib/Utf8/Utf8.h

@@ -1,11 +1,7 @@
 #pragma once
 
 #include <cstdint>
-#include <string>
+
 #define REPLACEMENT_GLYPH 0xFFFD
 
 uint32_t utf8NextCodepoint(const unsigned char** string);
-// Remove the last UTF-8 codepoint from a std::string and return the new size.
-size_t utf8RemoveLastChar(std::string& str);
-// Truncate string by removing N UTF-8 codepoints from the end.
-void utf8TruncateChars(std::string& str, size_t numChars);

scripts/debugging_monitor.py

@@ -1,214 +0,0 @@
-import sys
-import argparse
-import re
-import threading
-from datetime import datetime
-from collections import deque
-import time
-
-# Try to import potentially missing packages
-try:
-    import serial
-    from colorama import init, Fore, Style
-    import matplotlib.pyplot as plt
-    import matplotlib.animation as animation
-except ImportError as e:
-    missing_package = e.name
-    print("\n" + "!" * 50)
-    print(f" Error: The required package '{missing_package}' is not installed.")
-    print("!" * 50)
-
-    print(f"\nTo fix this, please run the following command in your terminal:\n")
-
-    install_cmd = "pip install "
-    packages = []
-    if 'serial' in str(e): packages.append("pyserial")
-    if 'colorama' in str(e): packages.append("colorama")
-    if 'matplotlib' in str(e): packages.append("matplotlib")
-
-    print(f"    {install_cmd}{' '.join(packages)}")
-
-    print("\nExiting...")
-    sys.exit(1)
-
-# --- Global Variables for Data Sharing ---
-# Store last 50 data points
-MAX_POINTS = 50
-time_data = deque(maxlen=MAX_POINTS)
-free_mem_data = deque(maxlen=MAX_POINTS)
-total_mem_data = deque(maxlen=MAX_POINTS)
-data_lock = threading.Lock() # Prevent reading while writing
-
-# Initialize colors
-init(autoreset=True)
-
-def get_color_for_line(line):
-    """
-    Classify log lines by type and assign appropriate colors.
-    """
-    line_upper = line.upper()
-
-    if any(keyword in line_upper for keyword in ["ERROR", "[ERR]", "[SCT]", "FAILED", "WARNING"]):
-        return Fore.RED
-    if "[MEM]" in line_upper or "FREE:" in line_upper:
-        return Fore.CYAN
-    if any(keyword in line_upper for keyword in ["[GFX]", "[ERS]", "DISPLAY", "RAM WRITE", "RAM COMPLETE", "REFRESH", "POWERING ON", "FRAME BUFFER", "LUT"]):
-        return Fore.MAGENTA
-    if any(keyword in line_upper for keyword in ["[EBP]", "[BMC]", "[ZIP]", "[PARSER]", "[EHP]", "LOADING EPUB", "CACHE", "DECOMPRESSED", "PARSING"]):
-        return Fore.GREEN
-    if "[ACT]" in line_upper or "ENTERING ACTIVITY" in line_upper or "EXITING ACTIVITY" in line_upper:
-        return Fore.YELLOW
-    if any(keyword in line_upper for keyword in ["RENDERED PAGE", "[LOOP]", "DURATION", "WAIT COMPLETE"]):
-        return Fore.BLUE
-    if any(keyword in line_upper for keyword in ["[CPS]", "SETTINGS", "[CLEAR_CACHE]"]):
-        return Fore.LIGHTYELLOW_EX
-    if any(keyword in line_upper for keyword in ["ESP-ROM", "BUILD:", "RST:", "BOOT:", "SPIWP:", "MODE:", "LOAD:", "ENTRY", "[SD]", "STARTING CROSSPOINT", "VERSION"]):
-        return Fore.LIGHTBLACK_EX
-    if "[RBS]" in line_upper:
-        return Fore.LIGHTCYAN_EX
-    if "[KRS]" in line_upper:
-        return Fore.LIGHTMAGENTA_EX
-    if any(keyword in line_upper for keyword in ["EINKDISPLAY:", "STATIC FRAME", "INITIALIZING", "SPI INITIALIZED", "GPIO PINS", "RESETTING", "SSD1677", "E-INK"]):
-        return Fore.LIGHTMAGENTA_EX
-    if any(keyword in line_upper for keyword in ["[FNS]", "FOOTNOTE"]):
-        return Fore.LIGHTGREEN_EX
-    if any(keyword in line_upper for keyword in ["[CHAP]", "[OPDS]", "[COF]"]):
-        return Fore.LIGHTYELLOW_EX
-
-    return Fore.WHITE
-
-def parse_memory_line(line):
-    """
-    Extracts Free and Total bytes from the specific log line.
-    Format: [MEM] Free: 196344 bytes, Total: 226412 bytes, Min Free: 112620 bytes
-    """
-    # Regex to find 'Free: <digits>' and 'Total: <digits>'
-    match = re.search(r"Free:\s*(\d+).*Total:\s*(\d+)", line)
-    if match:
-        try:
-            free_bytes = int(match.group(1))
-            total_bytes = int(match.group(2))
-            return free_bytes, total_bytes
-        except ValueError:
-            return None, None
-    return None, None
-
-def serial_worker(port, baud):
-    """
-    Runs in a background thread. Handles reading serial, printing to console,
-    and updating the data lists.
-    """
-    print(f"{Fore.CYAN}--- Opening {port} at {baud} baud ---{Style.RESET_ALL}")
-
-    try:
-        ser = serial.Serial(port, baud, timeout=0.1)
-        ser.dtr = False
-        ser.rts = False
-    except serial.SerialException as e:
-        print(f"{Fore.RED}Error opening port: {e}{Style.RESET_ALL}")
-        return
-
-    try:
-        while True:
-            try:
-                raw_data = ser.readline().decode('utf-8', errors='replace')
-
-                if not raw_data:
-                    continue
-
-                clean_line = raw_data.strip()
-                if not clean_line:
-                    continue
-
-                # Add PC timestamp
-                pc_time = datetime.now().strftime("%H:%M:%S")
-                formatted_line = re.sub(r"^\[\d+\]", f"[{pc_time}]", clean_line)
-
-                # Check for Memory Line
-                if "[MEM]" in formatted_line:
-                    free_val, total_val = parse_memory_line(formatted_line)
-                    if free_val is not None:
-                        with data_lock:
-                            time_data.append(pc_time)
-                            free_mem_data.append(free_val / 1024) # Convert to KB
-                            total_mem_data.append(total_val / 1024) # Convert to KB
-
-                # Print to console
-                line_color = get_color_for_line(formatted_line)
-                print(f"{line_color}{formatted_line}")
-
-            except OSError:
-                print(f"{Fore.RED}Device disconnected.{Style.RESET_ALL}")
-                break
-    except Exception as e:
-        # If thread is killed violently (e.g. main exit), silence errors
-        pass
-    finally:
-        if 'ser' in locals() and ser.is_open:
-            ser.close()
-
-def update_graph(frame):
-    """
-    Called by Matplotlib animation to redraw the chart.
-    """
-    with data_lock:
-        if not time_data:
-            return
-
-        # Convert deques to lists for plotting
-        x = list(time_data)
-        y_free = list(free_mem_data)
-        y_total = list(total_mem_data)
-
-    plt.cla() # Clear axis
-
-    # Plot Total RAM
-    plt.plot(x, y_total, label='Total RAM (KB)', color='red', linestyle='--')
-
-    # Plot Free RAM
-    plt.plot(x, y_free, label='Free RAM (KB)', color='green', marker='o')
-
-    # Fill area under Free RAM
-    plt.fill_between(x, y_free, color='green', alpha=0.1)
-
-    plt.title("ESP32 Memory Monitor")
-    plt.ylabel("Memory (KB)")
-    plt.xlabel("Time")
-    plt.legend(loc='upper left')
-    plt.grid(True, linestyle=':', alpha=0.6)
-
-    # Rotate date labels
-    plt.xticks(rotation=45, ha='right')
-    plt.tight_layout()
-
-def main():
-    parser = argparse.ArgumentParser(description="ESP32 Monitor with Graph")
-    parser.add_argument("port", nargs="?", default="/dev/ttyACM0", help="Serial port")
-    parser.add_argument("--baud", type=int, default=115200, help="Baud rate")
-    args = parser.parse_args()
-
-    # 1. Start the Serial Reader in a separate thread
-    # Daemon=True means this thread dies when the main program closes
-    t = threading.Thread(target=serial_worker, args=(args.port, args.baud), daemon=True)
-    t.start()
-
-    # 2. Set up the Graph (Main Thread)
-    try:
-        plt.style.use('light_background')
-    except:
-        pass
-
-    fig = plt.figure(figsize=(10, 6))
-
-    # Update graph every 1000ms
-    ani = animation.FuncAnimation(fig, update_graph, interval=1000)
-
-    try:
-        print(f"{Fore.YELLOW}Starting Graph Window... (Close window to exit){Style.RESET_ALL}")
-        plt.show()
-    except KeyboardInterrupt:
-        print(f"\n{Fore.YELLOW}Exiting...{Style.RESET_ALL}")
-        plt.close('all') # Force close any lingering plot windows
-
-if __name__ == "__main__":
-    main()

src/activities/home/HomeActivity.cpp

@@ -4,7 +4,6 @@
 #include <Epub.h>
 #include <GfxRenderer.h>
 #include <SDCardManager.h>
-#include <Utf8.h>
 #include <Xtc.h>
 
 #include <cstring>
@@ -367,7 +366,7 @@ void HomeActivity::render() {
         while (!lines.back().empty() && renderer.getTextWidth(UI_12_FONT_ID, lines.back().c_str()) > maxLineWidth) {
           // Remove "..." first, then remove one UTF-8 char, then add "..." back
           lines.back().resize(lines.back().size() - 3);  // Remove "..."
-          utf8RemoveLastChar(lines.back());
+          StringUtils::utf8RemoveLastChar(lines.back());
           lines.back().append("...");
         }
         break;
@@ -376,7 +375,7 @@ void HomeActivity::render() {
       int wordWidth = renderer.getTextWidth(UI_12_FONT_ID, i.c_str());
       while (wordWidth > maxLineWidth && !i.empty()) {
         // Word itself is too long, trim it (UTF-8 safe)
-        utf8RemoveLastChar(i);
+        StringUtils::utf8RemoveLastChar(i);
         // Check if we have room for ellipsis
         std::string withEllipsis = i + "...";
         wordWidth = renderer.getTextWidth(UI_12_FONT_ID, withEllipsis.c_str());
@@ -429,7 +428,7 @@ void HomeActivity::render() {
       if (!lastBookAuthor.empty()) {
         std::string trimmedAuthor = lastBookAuthor;
         while (renderer.getTextWidth(UI_10_FONT_ID, trimmedAuthor.c_str()) > maxLineWidth && !trimmedAuthor.empty()) {
-          utf8RemoveLastChar(trimmedAuthor);
+          StringUtils::utf8RemoveLastChar(trimmedAuthor);
         }
         if (renderer.getTextWidth(UI_10_FONT_ID, trimmedAuthor.c_str()) <
             renderer.getTextWidth(UI_10_FONT_ID, lastBookAuthor.c_str())) {
@@ -463,14 +462,14 @@ void HomeActivity::render() {
       // Trim author if too long (UTF-8 safe)
       bool wasTrimmed = false;
       while (renderer.getTextWidth(UI_10_FONT_ID, trimmedAuthor.c_str()) > maxLineWidth && !trimmedAuthor.empty()) {
-        utf8RemoveLastChar(trimmedAuthor);
+        StringUtils::utf8RemoveLastChar(trimmedAuthor);
         wasTrimmed = true;
       }
       if (wasTrimmed && !trimmedAuthor.empty()) {
         // Make room for ellipsis
         while (renderer.getTextWidth(UI_10_FONT_ID, (trimmedAuthor + "...").c_str()) > maxLineWidth &&
                !trimmedAuthor.empty()) {
-          utf8RemoveLastChar(trimmedAuthor);
+          StringUtils::utf8RemoveLastChar(trimmedAuthor);
         }
         trimmedAuthor.append("...");
       }

src/activities/reader/EpubReaderActivity.cpp

@@ -570,8 +570,8 @@ void EpubReaderActivity::renderStatusBar(const int orientedMarginRight, const in
         availableTitleSpace = rendererableScreenWidth - titleMarginLeft - titleMarginRight;
         titleMarginLeftAdjusted = titleMarginLeft;
       }
-      if (titleWidth > availableTitleSpace) {
-        title = renderer.truncatedText(SMALL_FONT_ID, title.c_str(), availableTitleSpace);
+      while (titleWidth > availableTitleSpace && title.length() > 11) {
+        title.replace(title.length() - 8, 8, "...");
         titleWidth = renderer.getTextWidth(SMALL_FONT_ID, title.c_str());
       }
     }

src/activities/reader/TxtReaderActivity.cpp

@@ -533,8 +533,8 @@ void TxtReaderActivity::renderStatusBar(const int orientedMarginRight, const int
 
     std::string title = txt->getTitle();
     int titleWidth = renderer.getTextWidth(SMALL_FONT_ID, title.c_str());
-    if (titleWidth > availableTextWidth) {
-      title = renderer.truncatedText(SMALL_FONT_ID, title.c_str(), availableTextWidth);
+    while (titleWidth > availableTextWidth && title.length() > 11) {
+      title.replace(title.length() - 8, 8, "...");
       titleWidth = renderer.getTextWidth(SMALL_FONT_ID, title.c_str());
     }
 

src/util/StringUtils.cpp

@@ -61,4 +61,23 @@ bool checkFileExtension(const String& fileName, const char* extension) {
   return localFile.endsWith(localExtension);
 }
 
+size_t utf8RemoveLastChar(std::string& str) {
+  if (str.empty()) return 0;
+  size_t pos = str.size() - 1;
+  // Walk back to find the start of the last UTF-8 character
+  // UTF-8 continuation bytes start with 10xxxxxx (0x80-0xBF)
+  while (pos > 0 && (static_cast<unsigned char>(str[pos]) & 0xC0) == 0x80) {
+    --pos;
+  }
+  str.resize(pos);
+  return pos;
+}
+
+// Truncate string by removing N UTF-8 characters from the end
+void utf8TruncateChars(std::string& str, const size_t numChars) {
+  for (size_t i = 0; i < numChars && !str.empty(); ++i) {
+    utf8RemoveLastChar(str);
+  }
+}
+
 }  // namespace StringUtils

src/util/StringUtils.h

@@ -19,4 +19,10 @@ std::string sanitizeFilename(const std::string& name, size_t maxLength = 100);
 bool checkFileExtension(const std::string& fileName, const char* extension);
 bool checkFileExtension(const String& fileName, const char* extension);
 
+// UTF-8 safe string truncation - removes one character from the end
+// Returns the new size after removing one UTF-8 character
+size_t utf8RemoveLastChar(std::string& str);
+
+// Truncate string by removing N UTF-8 characters from the end
+void utf8TruncateChars(std::string& str, size_t numChars);
 }  // namespace StringUtils