如何让QDockWidget在窗口调整大小时表现得如同中央部件

Hey there! Let's fix that annoying random QDockWidget resizing issue in your QOwnNotes setup. When you ditch the central widget, Qt's layout system defaults to distributing space arbitrarily between docks—but we can force it to prioritize your chosen dock like a central widget would. Here are two solid approaches:

Approach 1: Fake Central Widget (Most Reliable) #

Qt's QMainWindow relies on a central widget to anchor layout behavior, even if it's invisible. We can use this to our advantage:

1. Create a hidden placeholder widget as your "fake" central widget:

   QWidget *fakeCentral = new QWidget(this);
   fakeCentral->setVisible(false); // Keep it out of sight
   setCentralWidget(fakeCentral);
   

2. Split your target dock with this fake widget, then set stretch factors to prioritize the dock:

   // Replace `targetDock` with your specific QDockWidget instance
   splitDockWidget(targetDock, fakeCentral, Qt::Horizontal);
   
   // Make the target dock take all available resize space
   setStretchFactor(targetDock, 1);
   // Give the fake widget zero priority (it won't take any space)
   setStretchFactor(fakeCentral, 0);
   

Now when you resize the main window, your target dock will expand/shrink just like a real central widget, while other docks stay stable.

Approach 2: Size Policy & Stretch Factors (Simpler for Single-Area Docks) #

If all your docks are in the same area, you can tweak size policies and stretch weights directly:

1. Set your target dock to expand aggressively:

   targetDock->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);
   

2. Set other docks to maintain their preferred size instead of expanding:

   otherDock1->setSizePolicy(QSizePolicy::Preferred, QSizePolicy::Preferred);
   otherDock2->setSizePolicy(QSizePolicy::Preferred, QSizePolicy::Preferred);
   

3. Enforce stretch weights in the dock area to lock priorities:

   // Give target dock all the resize weight
   setStretchFactor(targetDock, 1);
   // Give other docks zero resize weight
   setStretchFactor(otherDock1, 0);
   setStretchFactor(otherDock2, 0);
   

Quick Tips for QOwnNotes #

• Make sure you enable dock nesting first with setDockNestingEnabled(true)—this keeps your complex layout from breaking.
• Double-check that existing QOwnNotes dock management code isn't overriding your stretch factors (look for any existing setStretchFactor calls).

内容的提问来源于stack exchange，提问作者Patrizio Bekerle