State Plugins Overview

Base Functions

State plugins is simple objects to work with MeshLib scene and/or objects. It is one of possible inheritance of MR::RibbonMenuItem

It has base functions:

Available function - MR::ISceneStateCheck interface function that block plugin in UI

Note

This fuction can be inherited from some helper classes MR::SceneStateExactCheck MR::SceneStateAtLeastCheck MR::SceneStateAtMostCheck MR::SceneStateOrCheck MR::SceneStateAndCheck

// return empty string if all requirements are satisfied, otherwise return first unsatisfied requirement
virtual std::string isAvailable( const std::vector<std::shared_ptr<const Object>>& ) const { return ""; }

On Enable function - will be called if user enables plugin (only possible if isAvailable has returned true), if onEnable_ function returns false plugin will not be enabled (useful for some expensive checks, not to do them in each frame available function)

MRVIEWER_API virtual bool onEnable_();

On Disable function - will be called if user disable plugin, it is necessary to clear all plugin data

MRVIEWER_API virtual bool onDisable_();

Draw Dialog function - this function is called in each frame, only if plugin is enabled (will not be called after onDisable_ function). It is necessary to show plugin custom UI.

MRVIEWER_API virtual void drawDialog( ImGuiContext* ctx );

How to make your first plugin

To create you plugin you need to inherit class from MR::StatePlugin or MR::StateListenerPlugin (in case you need to get some events)
Example:

class MyOwnPlugin : public MR::StatePlugin
{
public:
    MyOwnPlugin():MR::StatePlugin("My Plugin Name"){}
    virtual std::string isAvailable(const std::vector<std::shared_ptr<const MR::Object>>& selectedObjects) const override
    {
        if ( selectedObjects.size() == 1 )
            return "";
        return "Exactly one object should be selected";
    }
    virtual void drawDialog( ImGuiContext* ctx) override
    {
        auto windowSize = viewer->viewport().getViewportRect();
        auto menuWidth = 280.0f * UI::scale();
 
        ImGui::SetCurrentContext( ctx );
        ImGui::SetNextWindowPos( ImVec2( windowSize.width - menuWidth, 0 ), ImGuiCond_FirstUseEver );
        ImGui::SetNextWindowSize( ImVec2( menuWidth, 0 ), ImGuiCond_FirstUseEver );
        ImGui::SetNextWindowSizeConstraints( ImVec2( menuWidth, -1.0f ), ImVec2( menuWidth, -1.0f ) );
        ImGui::Begin( plugin_name.c_str(), &dialogIsOpen_, ImGuiWindowFlags_NoResize | ImGuiWindowFlags_AlwaysAutoResize );
 
        if (ImGui::Button("Some action"))
            someAction_();
 
        ImGui::End();
    }
 
private:
    std::shared_ptr<MR::Object> obj_;
 
    // some action of this plugin
    void someAction_();
 
    virtual bool onEnable_() override
    {
        obj_ = MR::getAllObjectsInTree<MR::Object>( &MR::SceneRoot::get(), MR::ObjectSelectivityType::Selected )[0];
        return true;
    }
    virtual bool onDisable_() override
    {
        obj_.reset();
        return true;
    }
}

Register your plugin with

MR_REGISTER_RIBBON_ITEM( MyOwnPlugin )

To show this item on Ribbon menu, it should be present in MenuSchema.ui.json file (special page about these files are coming soon)
MR::StateListenerPlugin is more simple way to make plugin listen to some events:

// This plugin will listen to mouse move and mouse down, also isAvailable function will be imlemented with SceneStateExactCheck
class MyListenerPlugin : public StateListenerPlugin<MouseMoveListener,MouseDownListener>, public SceneStateExactCheck<1, ObjectMesh>

Find more: MR::RibbonMenuItem MR::StateBasePlugin MR::StateListenerPlugin