enable keybindings for unavailable operations -> show info message

this should make it easier to discover what a given keypress was supposed to do (e.g. which operation it triggered)

closes #9896

modules/behavior/operation.js

@@ -1,3 +1,5 @@
+import { t } from '../core';
+
 /* Creates a keybinding behavior for an operation */
 export function behaviorOperation(context) {
     var _operation;
@@ -7,19 +9,26 @@ export function behaviorOperation(context) {
         // prevent operations during low zoom selection
         if (!context.map().withinEditableZoom()) return;
 
-        if (_operation.availableForKeypress && !_operation.availableForKeypress()) return;
+        // ignore (temporarily) disabled operation keyboard shortcuts,
+        // e.g. Ctrl+C while text is selected
+        if (_operation.availableForKeypress?.() === false) return;
 
         d3_event.preventDefault();
 
-        var disabled = _operation.disabled();
-
-        if (disabled) {
+        if (!_operation.available()) {
+            context.ui().flash
+                .duration(4000)
+                .iconName('#iD-operation-' + _operation.id)
+                .iconClass('operation disabled')
+                .label(t.append('operations._unavailable', {
+                    operation: t(`operations.${_operation.id}.title`) || _operation.id
+                }))();
+        } else if (_operation.disabled()) {
             context.ui().flash
                 .duration(4000)
                 .iconName('#iD-operation-' + _operation.id)
                 .iconClass('operation disabled')
                 .label(_operation.tooltip())();
-
         } else {
             context.ui().flash
                 .duration(2000)
@@ -35,14 +44,19 @@ export function behaviorOperation(context) {
 
     function behavior() {
         if (_operation && _operation.available()) {
-            context.keybinding()
-                .on(_operation.keys, keypress);
+            behavior.on();
         }
 
         return behavior;
     }
 
 
+    behavior.on = function() {
+        context.keybinding()
+            .on(_operation.keys, keypress);
+    };
+
+
     behavior.off = function() {
         context.keybinding()
             .off(_operation.keys);

modules/modes/select.js

@@ -192,7 +192,6 @@ export function modeSelect(context, selectedIDs) {
     };
 
     function loadOperations() {
-
         _operations.forEach(function(operation) {
             if (operation.behavior) {
                 context.uninstall(operation.behavior);
@@ -200,29 +199,39 @@ export function modeSelect(context, selectedIDs) {
         });
 
         _operations = Object.values(Operations)
-            .map(function(o) { return o(context, selectedIDs); })
-            .filter(function(o) { return o.id !== 'delete' && o.id !== 'downgrade' && o.id !== 'copy'; })
+            .map(o => o(context, selectedIDs))
+            .filter(o => o.id !== 'delete' && o.id !== 'downgrade' && o.id !== 'copy')
             .concat([
                 // group copy/downgrade/delete operation together at the end of the list
                 Operations.operationCopy(context, selectedIDs),
                 Operations.operationDowngrade(context, selectedIDs),
                 Operations.operationDelete(context, selectedIDs)
-            ]).filter(function(operation) {
-                return operation.available();
+            ]);
+
+        _operations
+            .filter(operation => operation.available())
+            .forEach(operation => {
+                if (operation.behavior) {
+                    context.install(operation.behavior);
+                }
             });
 
-        _operations.forEach(function(operation) {
-            if (operation.behavior) {
-                context.install(operation.behavior);
-            }
-        });
+        // unavailable operations: still install keybindings
+        // to show information message about the unavailability of the operation
+        _operations
+            .filter(operation => !operation.available())
+            .forEach(operation => {
+                if (operation.behavior) {
+                    operation.behavior.on();
+                }
+            });
 
         // remove any displayed menu
         context.ui().closeEditMenu();
     }
 
     mode.operations = function() {
-        return _operations;
+        return _operations.filter(operation => operation.available());
     };
 
 
@@ -638,7 +647,7 @@ export function modeSelect(context, selectedIDs) {
 
         _focusedVertexIds = null;
 
-        _operations.forEach(function(operation) {
+        _operations.forEach(operation => {
             if (operation.behavior) {
                 context.uninstall(operation.behavior);
             }

modules/operations/copy.js

@@ -104,9 +104,9 @@ export function operationCopy(context, selectedIDs) {
 
 
     operation.availableForKeypress = function() {
-        var selection = window.getSelection && window.getSelection();
+        const selection = window.getSelection?.();
         // if the user has text selected then let them copy that, not the selected feature
-        return !selection || !selection.toString();
+        return !selection?.toString();
     };
 
 

modules/util/keybinding.js

@@ -12,7 +12,6 @@ export function utilKeybinding(namespace) {
     function testBindings(d3_event, isCapturing) {
         var didMatch = false;
         var bindings = Object.keys(_keybindings).map(function(id) { return _keybindings[id]; });
-        var i, binding;
 
         // Most key shortcuts will accept either lower or uppercase ('h' or 'H'),
         // so we don't strictly match on the shift key, but we prioritize
@@ -20,8 +19,7 @@ export function utilKeybinding(namespace) {
         // (This lets us differentiate between '←'/'⇧←' or '⌘Z'/'⌘⇧Z')
 
         // priority match shifted keybindings first
-        for (i = 0; i < bindings.length; i++) {
-            binding = bindings[i];
+        for (const binding of bindings) {
             if (!binding.event.modifiers.shiftKey) continue;  // no shift
             if (!!binding.capture !== isCapturing) continue;
             if (matches(d3_event, binding, true)) {
@@ -36,8 +34,7 @@ export function utilKeybinding(namespace) {
         if (didMatch) return;
 
         // then unshifted keybindings
-        for (i = 0; i < bindings.length; i++) {
-            binding = bindings[i];
+        for (const binding of bindings) {
             if (binding.event.modifiers.shiftKey) continue;   // shift
             if (!!binding.capture !== isCapturing) continue;
             if (matches(d3_event, binding, false)) {