Fly View Customization

The Fly View is designed in such a way that it can be cusomtized in multiple ways from simple to more complex. It is designed in three separate layers each of which are customizable providing different levels of change.

Layers

• There are three layers to the fly view from top to bottom visually:
  • FlyView.qml 这是控制地图和视频切换的 ui 和业务逻辑的基层。
  • FlyViewWidgetsOverlay.qml This layer includes all the remaining widgets for the fly view.
  • FlyViewCustomLayer.qml This is a layer you override using resource override to add your own custom layer.

Inset Negotiation using QGCToolInsets

An important aspect of the Fly View is that it needs to understand how much central space it has in the middle of it's map window which is not obstructed by ui widgets which are at the edges of the window. 它使用这个信息在载具失去视图时绘制地图。 这不仅需要为窗口边缘做到，而且需要为小部件本身做到这一点，以使地图在小部件下面之前移动。

This is done through the use of the QGCToolInsets object included in each layer. This objects provides inset information for each window edge informing the system as to how much real estate is taken up by edge based ui. Each layer is given the insets of the layer below it through parentToolInsets and then reports back the new insets taking into account the layer below and it's own additions through toolInsets. The final results total inset is then given to the map so it can do the right thing. The best way to understand this is to look at both the upstream and custom example code.

FlyView.qml

The base layer for the view is also the most complex from ui interactions and business logic. 它包括地图和录像的主要显示元素以及有导向的控制。 Although you can resource override this layer it is not recommended. And if you do you better really (really) know what you are doing. The reason it is a separate layer is to make the layer above much simpler and easier to customize.

FlyViewWidgetsOverlay.qml

This layer contains all the remaining controls of the fly view. You have the ability to hide the controls through use of QGCFlyViewOptions. But in order to change the layout of the upstream controls you must use a resource override. If you look at the source you'll see that the controls themselves are well encapsulated such that it should not be that difficult to create your own override which repositions them and/or adds your own ui. While maintaining a connection to the upstream implementaions of the controls.

FlyViewCustomLayer.qml

This provides the simplest customization ability to the Fly View. Allowing you the add ui elements which are additive to the existing upstream controls. The upstream code adds no ui elements and is meant to be the basis for your own custom code used as a resource override for this qml. The custom example code provides you with an example of how to do it.

Recommendations

Simple customization

The best place to start is using a custom layer override plus turning off ui elements from the widgets layer (if needed). 如果可能的话，我建议尽量只使用这个。 It provides the greatest abilty to not get screwed by upstream changes in the layers below.

Moderate complexity customization

如果你真的需要重新定位上游的ui元素，那么你唯一的选择是覆盖 FlyViewWidgetsOverlay.qml。 By doing this you are distancing yourself a bit from upstream changes. Although you will still get changes in the upstream controls for free. If there is a whole new control added to the fly view upstream you won't get it until you add it to your own override.

Highly complex customization

The last and least recommended customization mechanism is overriding FlyView.qml. By doing this you are distancing yourself even further from getting upstream changes for free.