1. Techniques
1.1. AJAX forms
1.2. File upload buttons
1.3. Hook submit
1.4. Rendering panes
1.4.1. use ctools_content_render
1.4.2. Render ctools content type programatically
1.5. Resources
1.5.1. ctools advanced help
1.5.2. ctools example modules
1.5.3. ctools video
2. What to do
2.1. How to build a new widget
2.1.1. Link to example
2.2. Display the rendered pane in the style selection window
2.2.1. Add a css file to the pane
2.2.2. => Find how to access the panel objet from the panel style settings form
2.2.2.1. Best case, it's already there
2.2.2.2. Worst case, adding a new arg will require creating a new display renderer
2.2.3. panels_renderer_standard.render_pane_content will render the pane
2.2.3.1. calls ctools_content_render
2.2.3.2. panels/plugins/display_renderers/panels_renderer_Standard.class.php line 541, inside the panels_renderer_standard class
2.3. Ability to save to file
2.3.1. Find out how to add a new submit hook to the form
2.3.2. How to get the drupal files directory
2.3.3. Save the css to a subdirectory of the new drupal files directory
2.3.3.1. I've created an example of how to save a file here: spiral_panels_form_panels_edit_style_type_form_submit
2.4. Display the custom pane according to the selected style
3. Style Selection Screen
3.1. features
3.1.1. css override per panel
3.1.1.1. file selection
3.1.1.1.1. existing files
3.1.1.1.2. upload new files
3.1.1.2. Style preview
3.1.1.2.1. Mini panel? Iframe
3.1.2. js selection & override
3.1.2.1. in the 2nd params screen?
3.1.2.2. file selection
3.1.2.2.1. existing files
3.1.2.2.2. upload new files
4. Rendering
4.1. Include the custom style selected for the pane
4.2. AJAX progressive buildup
4.2.1. check the ctools ajax example plugin
5. Other targets
5.1. External module, built for future sharing with the community
6. Open Issues
6.1. Where to save the css/js files?
6.1.1. database
6.1.1.1. e.g. like the stylizer module
6.1.2. filesystem
6.1.2.1. Tzachi: This is preferrable
7. Things to check
7.1. How to integrate views?
7.2. Fieldable panel panes
8. Widget Arguments Screen
8.1. info
8.1.1. Widgets = content types
8.2. Widgets Argument Selection
8.3. Edit Widget Arguments screen?
9. Implementation
9.1. Panel per node type
9.1.1. Use variants
9.1.1.1. selection rules
9.1.2. Use Panelizer?
9.1.2.1. @proof of concept