# Rich Editor Image Editing - Verification Guide

## ✅ Implemented Features

### 1. **Image Selection**
- ✓ Click on any image in the editor to select it
- ✓ Selected image shows a blue outline (3px solid #3182ce)
- ✓ Blue shadow effect for visual feedback
- ✓ Cursor changes to 'move' when hovering over selected image

### 2. **Image Resizing** 🔵
- ✓ Blue circular resize handle appears at bottom-right corner
- ✓ Handle size: 16px with white border and blue gradient
- ✓ Hover effect: scales to 1.3x and enhanced shadow
- ✓ Drag the handle to resize image proportionally
- ✓ Min width: 50px, Max width: editor width - 40px
- ✓ Handle position updates on scroll
- ✓ Width is tracked and displayed in toolbar

### 3. **Image Alignment** 🎯
- ✓ **Align Left**: Image positioned on left side
- ✓ **Align Center**: Image centered horizontally
- ✓ **Align Right**: Image positioned on right side
- ✓ Buttons use Teal color scheme for visibility
- ✓ Drag image left/right (>40px movement) for quick alignment

### 4. **Width Control** 📏
- ✓ Current width display in pixels
- ✓ Manual width input field
- ✓ "Nastavit" button to apply width
- ✓ Press Enter in input field to apply
- ✓ Width validation (min: 50px, max: editor width)
- ✓ Toast notification on successful width change

### 5. **Image Transformations** 🔄
- ✓ **Rotate Left**: Rotate -90 degrees
- ✓ **Rotate Right**: Rotate +90 degrees
- ✓ **Flip Horizontal**: Mirror horizontally
- ✓ **Flip Vertical**: Mirror vertically
- ✓ Visual feedback: active buttons show solid style
- ✓ Rotations accumulate (0°, 90°, 180°, 270°)

### 6. **Image Filters** 🎨
- ✓ **Brightness**: 0-200% (slider)
- ✓ **Contrast**: 0-200% (slider)
- ✓ **Saturation**: 0-200% (slider)
- ✓ **Blur**: 0-10px with 0.5 step (slider)
- ✓ **Quick Filters**:
  - Grayscale toggle (black & white)
  - Sepia toggle (vintage effect)
- ✓ Real-time preview as you adjust
- ✓ Filter persistence via data-filters attribute

### 7. **Image Management** 🗑️
- ✓ **Delete button**: Remove selected image
- ✓ **Reset filters**: Restore default filter values
- ✓ **Delete/Backspace key**: Delete selected image
- ✓ Toast notifications for all actions

### 8. **Floating Toolbar** 📱
- ✓ Appears next to selected image
- ✓ Intelligent positioning (right side preferred, left if no space)
- ✓ Sections: Alignment, Width, Transformations, Filters
- ✓ Scrollable if content exceeds 80vh
- ✓ Custom scrollbar styling
- ✓ Min width: 320px, Max width: 380px
- ✓ Click outside toolbar keeps it open until X button clicked
- ✓ Backdrop blur on close button

### 9. **Image Upload & Cropping** 📸
- ✓ "Vložit obrázek" button above editor
- ✓ Image button in Quill toolbar
- ✓ Crop modal with ReactCrop library
- ✓ Quality control (1-100%, default 85%)
- ✓ Max width control (100-3000px, default 1500px)
- ✓ Smart canvas downscaling for performance
- ✓ High-quality image smoothing

### 10. **UX Improvements** 💫
- ✓ Improved resize handle visibility (larger, better shadows)
- ✓ Scroll event handling for handle positioning
- ✓ Enhanced hover states on all controls
- ✓ Comprehensive helper text with bullet points
- ✓ All Czech language labels and tooltips
- ✓ Color-coded button groups (teal for alignment, blue for transforms)

## 🧪 Testing Checklist

### Basic Image Operations
- [ ] Upload an image using the "Vložit obrázek" button
- [ ] Crop the image using the crop tool
- [ ] Click on the inserted image to select it
- [ ] Verify blue outline appears around selected image
- [ ] Verify resize handle appears at bottom-right corner

### Resizing Tests
- [ ] Hover over resize handle - should scale to 1.3x
- [ ] Drag resize handle right - image should grow
- [ ] Drag resize handle left - image should shrink
- [ ] Verify minimum width (50px) is enforced
- [ ] Verify maximum width (editor width) is enforced
- [ ] Check width updates in toolbar during resize

### Alignment Tests
- [ ] Click "Align Left" button - image moves to left
- [ ] Click "Align Center" button - image centers
- [ ] Click "Align Right" button - image moves to right
- [ ] Drag image left (>40px) - should align left
- [ ] Drag image right (>40px) - should align right

### Width Control Tests
- [ ] Type a width value (e.g., 400) in the input
- [ ] Click "Nastavit" button - image should resize
- [ ] Press Enter in input field - should also resize
- [ ] Try invalid width (e.g., -100) - should show warning
- [ ] Verify current width display is accurate

### Transformation Tests
- [ ] Click "Rotate Left" 4 times - should return to original
- [ ] Click "Rotate Right" 4 times - should return to original
- [ ] Toggle "Flip Horizontal" - image should mirror
- [ ] Toggle "Flip Vertical" - image should flip
- [ ] Combine multiple transformations

### Filter Tests
- [ ] Adjust Brightness slider (0-200%) - verify effect
- [ ] Adjust Contrast slider (0-200%) - verify effect
- [ ] Adjust Saturation slider (0-200%) - verify effect
- [ ] Adjust Blur slider (0-10px) - verify effect
- [ ] Click "Černobílá" - should toggle grayscale
- [ ] Click "Sepia" - should toggle sepia effect
- [ ] Apply multiple filters simultaneously
- [ ] Click "Reset filters" - all should return to defaults

### Deletion Tests
- [ ] Select image and click delete button
- [ ] Select image and press Delete key
- [ ] Select image and press Backspace key
- [ ] Verify toast notification appears

### Persistence Tests
- [ ] Apply filters to an image
- [ ] Deselect and reselect the image
- [ ] Verify filters are still applied
- [ ] Save the article and reload
- [ ] Verify filters persist after reload

### Toolbar Tests
- [ ] Verify toolbar appears to the right of image (if space)
- [ ] Verify toolbar appears to the left if no space on right
- [ ] Scroll the editor - verify toolbar stays positioned
- [ ] Verify toolbar is scrollable if tall
- [ ] Click X button to close toolbar

### Edge Cases
- [ ] Select image, scroll editor - verify handle follows
- [ ] Upload very large image - verify it's constrained
- [ ] Upload very small image - verify it can be resized
- [ ] Try all operations with multiple images in editor
- [ ] Test in narrow browser window
- [ ] Test in wide browser window

## 📊 Technical Details

### Key Components Modified
- **CustomRichEditor.tsx**: Main rich editor component
  - Added state for imageWidth and manualWidth
  - Enhanced resize handle with better positioning
  - Added alignment functions
  - Added manual width input handler
  - Improved scroll event handling
  - Enhanced toolbar UI with new sections

### New Functions
1. `alignImage(alignment: 'left' | 'center' | 'right')` - Aligns selected image
2. `applyManualWidth()` - Applies manually entered width value
3. `handleScroll()` - Updates resize handle position on scroll

### Enhanced Functions
1. `createResizeHandle()` - Better styling, scroll-aware positioning
2. `selectImage()` - Loads current width, resets filters properly
3. `deselectImage()` - Clears width state
4. `handleMouseDown()` - Improved drag threshold (40px vs 30px)

### CSS Improvements
- Enhanced resize handle visibility (16px, better shadows)
- Custom scrollbar for floating toolbar
- Improved hover states

### Filter Persistence
- Filters stored in `data-filters` attribute as JSON
- Loaded when image is selected
- Preserved through all operations
- Sanitized by DOMPurify with proper configuration

## 🎯 Expected Behavior Summary

**When you click an image:**
1. Blue outline appears (3px solid)
2. Blue shadow effect added
3. Resize handle appears at bottom-right (blue circle with white border)
4. Floating toolbar opens next to image
5. Current width loads in toolbar
6. Any saved filters are restored

**When you resize:**
1. Drag blue handle to desired size
2. Width updates in real-time
3. Width displayed in toolbar updates
4. Image maintains aspect ratio
5. Handle follows image on scroll

**When you align:**
1. Click alignment button (left/center/right)
2. Image repositions immediately
3. Toast notification confirms action
4. OR drag image left/right >40px for quick alignment

**When you filter:**
1. Adjust sliders or click quick filters
2. Image updates in real-time
3. Filter data saved to image
4. Filters persist when reselecting image

**When you delete:**
1. Click delete button or press Delete/Backspace
2. Image removed from editor
3. Toast notification shows confirmation
4. Toolbar closes

## 🚀 Performance Notes

- **Image Upload**: Optimized with quality and max-width controls
- **Canvas Rendering**: High-quality smoothing enabled
- **Real-time Filters**: CSS filters (hardware accelerated)
- **Resize Handle**: Only updates on relevant events
- **Toolbar**: Scrollable for performance with many controls

## 📝 Known Limitations

1. **Drag Movement**: Currently changes alignment, not free positioning
2. **Filter Presets**: Only grayscale and sepia quick filters
3. **Undo/Redo**: Standard browser undo may not work for all operations
4. **Mobile**: Touch events not specifically optimized (works but not ideal)

## ✨ Recommended Improvements for Future

1. Add more filter presets (vintage, cold, warm, etc.)
2. Add free-form positioning with drag
3. Add image border/padding controls
4. Add image link functionality
5. Add alt text editing in toolbar
6. Add image caption support
7. Optimize for touch/mobile devices
8. Add keyboard shortcuts for common operations
9. Add image history/undo specifically for filters

---

**Version**: Enhanced Image Editing v2.0  
**Date**: October 19, 2025  
**Status**: ✅ Ready for Testing