Fixed Issue #1942 [BUG] Some modifying actions can still be performed

app/src/actioncommands.cpp

@@ -844,12 +844,17 @@ void ActionCommands::duplicateKey()
 void ActionCommands::moveFrameForward()
 {
     Layer* layer = mEditor->layers()->currentLayer();
-    if (layer)
+    if (layer == nullptr) { return; }
+
+    // Prevent moving keyframe if the layer is not visible, as it can cause confusion to users when they don't see their keyframe move.
+    if (!layer->visible()) {
+        mEditor->getScribbleArea()->showLayerNotVisibleWarning();
+        return;
+    }
+
+    if (layer->moveKeyFrame(mEditor->currentFrame(), 1))
     {
-        if (layer->moveKeyFrame(mEditor->currentFrame(), 1))
-        {
-            mEditor->scrubForward();
-        }
+        mEditor->scrubForward();
     }
     mEditor->layers()->notifyAnimationLengthChanged();
     emit mEditor->framesModified();
@@ -858,12 +863,17 @@ void ActionCommands::moveFrameForward()
 void ActionCommands::moveFrameBackward()
 {
     Layer* layer = mEditor->layers()->currentLayer();
-    if (layer)
+    if (layer == nullptr) { return; }
+
+    // Moving keyframes on hidden layers is not allowed, as it can cause confusion. We show a warning to the user to let them know they need to unhide the layer first.
+    if (!layer->visible()) {
+        mEditor->getScribbleArea()->showLayerNotVisibleWarning();
+        return;
+    }
+
+    if (layer->moveKeyFrame(mEditor->currentFrame(), -1))
     {
-        if (layer->moveKeyFrame(mEditor->currentFrame(), -1))
-        {
-            mEditor->scrubBackward();
-        }
+        mEditor->scrubBackward();
     }
     emit mEditor->framesModified();
 }

core_lib/src/interface/editor.cpp

@@ -243,6 +243,12 @@ void Editor::pasteFromPreviousFrame()
         return;
     }
 
+    // Prevents pasting on an invisible layer, as this is likely a mistake and can be confusing for users, so show a warning and prevent the action
+    if (!currentLayer->visible()) {
+        mScribbleArea->showLayerNotVisibleWarning();
+        return;
+    }
+
     if (currentLayer->type() == Layer::BITMAP)
     {
         backup(tr("Paste from Previous Keyframe"));
@@ -357,6 +363,12 @@ void Editor::paste()
 
     if (!canPaste()) { return; }
 
+    // Prevents pasting on an invisible layer, as this is likely a mistake and can be confusing for users, so show a warning and prevent the action
+    if (!currentLayer->visible()) {
+        mScribbleArea->showLayerNotVisibleWarning();
+        return;
+    }
+
     if (clipboards()->framesIsEmpty()) {
 
         backup(tr("Paste"));
@@ -806,6 +818,13 @@ void Editor::selectAll() const
     Layer* layer = layers()->currentLayer();
 
     QRectF rect;
+
+    // Prevents Selection of an invisible layer, as this is likely a mistake and can be confusing for users, so show a warning and prevent the action
+    if (!layer->visible()) {
+        mScribbleArea->showLayerNotVisibleWarning();
+        return;
+    }
+
     if (layer->type() == Layer::BITMAP)
     {
         // Selects the drawn area (bigger or smaller than the screen). It may be more accurate to select all this way
@@ -989,6 +1008,10 @@ void Editor::switchVisibilityOfLayer(int layerNumber)
 {
     Layer* layer = mObject->getLayer(layerNumber);
     if (layer != nullptr) layer->switchVisibility();
+
+    // Deselect all to prevent confusion, as the user might have selected something on a layer that is now invisible, and this could lead to confusion
+    deselectAll();
+
     mScribbleArea->onLayerChanged();
 
     emit updateTimeLine();

core_lib/src/interface/scribblearea.cpp

@@ -1474,6 +1474,12 @@ void ScribbleArea::clearImage()
     Layer* layer = mEditor->layers()->currentLayer();
     if (layer == nullptr) { return; }
 
+    // Clearing an invisible layer is likely a mistake, so show a warning and prevent the action
+    if (!layer->visible()) {
+        showLayerNotVisibleWarning();
+        return;
+    }
+
     if (layer->type() == Layer::VECTOR)
     {
         mEditor->backup(tr("Clear Image", "Undo step text"));

core_lib/src/structure/layer.cpp

@@ -238,6 +238,10 @@ void Layer::removeFromSelectionList(int position)
 
 bool Layer::moveKeyFrame(int position, int offset)
 {
+    if (!visible()) {
+        return false;
+    }
+
     int newPos = position + offset;
     if (newPos < 1) { return false; }
 

core_lib/src/tool/selecttool.cpp

@@ -216,6 +216,7 @@ bool SelectTool::maybeDeselect(const QPointF& pos)
  */
 void SelectTool::keepSelection(Layer* currentLayer)
 {
+
     if (currentLayer->type() == Layer::VECTOR)
     {
         VectorImage* vectorImage = static_cast<LayerVector*>(currentLayer)->getLastVectorImageAtFrame(mEditor->currentFrame(), 0);