Source Code for Demo 2D Text Drawer

Location

./src/examples/src/textdrawer

This example shows:

• how to create a custom drawer.
• how to use the IFont interface.
• how to use the cColor class.
• how to use the canvas inside the Draw method.

Header

#pragma once
 
#include <adtfdisplaytoolboxdrawer/drawer.h>
 
class cTextDrawer : public adtf::ucom::object<adtf::disptb::drawerlib::cDrawer>
{
public:
    ADTF_CLASS_ID_NAME(cTextDrawer, "demo_text.2d_drawer.disptb.cid", "Demo 2D Text Drawer");

    cTextDrawer();

    ~cTextDrawer() = default;

    tResult Init(tInitStage eStage) override;
    tResult Shutdown(tInitStage eStage) override;

    tResult Draw(const adtf::ucom::iobject_ptr<adtf::disptb::graphicslib::ICanvas>& pCanvas) override;

    tResult ContextCreated(const adtf::ucom::iobject_ptr<adtf::disptb::graphicslib::ICanvas>& pCanvas) override;

    tResult ContextDestroyed() override;
 
private:
    adtf::base::property_variable<adtf_util::cString> m_strText;
    adtf::base::property_variable<adtf_util::cString> m_strColor;
    adtf::base::property_variable<tBool> m_bProjection;
    adtf::base::property_variable<tBool> m_bFlip;
    adtf::base::property_variable<tInt> m_nFontSize;
    adtf::base::property_variable<tFloat64> m_nRotation;
 
    adtf::disptb::graphicslib::cColor m_oColor;
    adtf::disptb::graphicslib::IFont* m_pFont;
};

Implementation

#include "text_drawer.h"
#include <adtfdisplaytoolboxgraphics/color.h>
#include <adtfdisplaytoolboxgraphics/gfxlibinterfaces.h>
 
#ifdef WIN32
    #include <windows.h>
    #undef CreateFont
#endif
 
ADTF_PLUGIN_VERSION(
    "Demo 2D Text Drawer Plugin", disptb, DISPTB_VERSION_MAJOR, DISPTB_VERSION_MINOR, DISPTB_VERSION_PATCH, cTextDrawer)
 
cTextDrawer::cTextDrawer():
    m_strText("Hello World!"), m_strColor("#000000ff"), m_bProjection(tTrue), m_nFontSize(11), m_nRotation(0)
{
    m_strText.SetDescription("Text to display. Linebreaks with LF character are used as such.");
    RegisterPropertyVariable("Text", m_strText);
 
    m_strColor.SetDescription("Text color key in format #RRGGBBAA.");
    RegisterPropertyVariable("Color", m_strColor);
 
    m_bProjection.SetDescription(
        "If enabled, scale and rotate the text according to the projection. Otherwise render projection-indepent.");
    RegisterPropertyVariable("Projection", m_bProjection);
 
    m_bFlip.SetDescription("If enabled, flip the text upside down");
    RegisterPropertyVariable("Flip", m_bFlip);
 
    m_nFontSize.SetDescription("Font size in pt.");
    m_nFontSize.SetValidRange(1, 80);
    RegisterPropertyVariable("Fontsize", m_nFontSize);
 
    m_nRotation.SetDescription("Text rotation in degree.");
    m_nRotation.SetValidRange(0, 360);
    RegisterPropertyVariable("Rotation", m_nRotation);
 
    SetDescription("Use this Drawer to paint a given string as pixels onto canvas.");
    SetHelpLink("$(ADTF_DISPLAY_TOOLBOX_DIR)/doc/html/page_2d_text_drawer_readme.html");
}
 
tResult cTextDrawer::Init(tInitStage eStage)
{
    RETURN_IF_FAILED(cDrawer::Init(eStage));
    adtf_util::cString color = m_strColor;
    adtf::disptb::graphicslib::cColor::ColorFromString(color, m_oColor);
    RETURN_NOERROR;
}
 
tResult cTextDrawer::Shutdown(tInitStage eStage)
{
    RETURN_IF_FAILED(cDrawer::Shutdown(eStage));
    RETURN_NOERROR;
}
 
tResult cTextDrawer::Draw(const adtf::ucom::iobject_ptr<adtf::disptb::graphicslib::ICanvas>& pCanvas)
{
    adtf_util::cString color = m_strColor;
    adtf::disptb::graphicslib::cColor::ColorFromString(color, m_oColor);
    adtf_util::cString text = m_strText;
 
    pCanvas->Font(m_pFont);
    pCanvas->SetFontAngle(*m_nRotation);
    pCanvas->SetFlag(adtf::disptb::graphicslib::CANVAS_FLAG_TEXT_FLIP_HORIZONTALLY, *m_bFlip);
    pCanvas->SetFlag(adtf::disptb::graphicslib::CANVAS_FLAG_TEXT_BASELINE_ON_TOP, tFalse);
    pCanvas->SetFlag(adtf::disptb::graphicslib::CANVAS_FLAG_TEXT_SCALE_WITH_COORDINATE_SYSTEM, *m_bProjection);
    pCanvas->SetFlag(adtf::disptb::graphicslib::CANVAS_FLAG_TEXT_ROTATE_WITH_COORDINATE_SYSTEM, *m_bProjection);
    pCanvas->Color(&m_oColor);
    pCanvas->OutputText(0, 0, "%s", text.GetPtr());
 
    RETURN_NOERROR;
}
 
tResult cTextDrawer::ContextCreated(const adtf::ucom::iobject_ptr<adtf::disptb::graphicslib::ICanvas>& pCanvas)
{
    m_pFont = pCanvas->CreateFont("arial", *m_nFontSize, adtf::disptb::graphicslib::IFont::STYLE_Default);
    RETURN_NOERROR;
}
 
tResult cTextDrawer::ContextDestroyed()
{
    if (m_pFont)
    {
        delete m_pFont;
        m_pFont = nullptr;
    }
    RETURN_NOERROR;
}