pub const DRAG_REGION_SCRIPT: &str = "(()=>{const p=m=>window.webuiHostPostMessage&&window.webuiHostPostMessage(JSON.stringify(m));const d=e=>{const q=typeof e.composedPath===\'function\'?e.composedPath():[];for(let i=0;i<q.length;i++){const n=q[i];if(!n||n.nodeType!==1)continue;if(n.hasAttribute(\'webui-no-drag\'))return false;if(n.hasAttribute(\'webui-drag\'))return true}return false};let a=null,w=!!window.chrome?.webview;document.addEventListener(\'pointerdown\',e=>{a=null;if(e.button!==0||!d(e))return;if(!w){p(\'start-drag\');return}a=[e.pointerId,e.screenX,e.screenY]});if(w){document.addEventListener(\'pointermove\',e=>{if(!a||e.pointerId!==a[0])return;if(!(e.buttons&1)){a=null;return}if(Math.abs(e.screenX-a[1])<4&&Math.abs(e.screenY-a[2])<4)return;a=null;p(\'start-drag\')});const end=e=>{if(a&&e.pointerId===a[0])a=null};document.addEventListener(\'pointerup\',end);document.addEventListener(\'pointercancel\',end);window.addEventListener(\'blur\',()=>{a=null})}document.addEventListener(\'dblclick\',e=>{if(e.button===0&&d(e))p(\'toggle-maximize\')})})();";Expand description
Shared script for [webui-drag] and [webui-no-drag] regions. Backends expose window.webuiHostPostMessage.
Script injected by every backend to translate webui-drag regions into host
messages.
The walk uses composedPath() rather than target.closest() because WebUI
renders through Web Components: a document-level listener sees shadow DOM
events retargeted to the host element, so closest() would never observe a
drag region declared inside a component’s shadow root. The path is scanned
from the innermost node outward, so the nearest webui-drag or
webui-no-drag ancestor wins, and non-element entries such as document
and window are skipped. WebView2 waits for pointer movement before
starting a native drag, since its move loop would consume a double-click.