Direct2D image list viewer

Brief

A small Direct2D playground project that demonstrates some basics of the API usage (C++17).

The view uses ID2D1DeviceContext to render with DXGI swapchain attached to a window based on this article.

There are 4 image layous implemented:

• aligned to left
• aligned to right of the widest image in the list
• aligned to the center of the widest image in the list
• horizontal flow - the images are composed by rows dynamically based on the window size

Basic zooming with Ctrl+Mousewheel is implemented. The scrolls are custom since only ID2D1DCRenderTarget supports Windows-provided scrolling.

Model

Initially the view was supposed to draw multi-page documents such as TIFF. For this purpose, there is an IDocument interface that represents a document itslef and an IPage interface representing individual IDocument's pages bitmaps.

The IDocumentModel hides this multi-level mess for the view. It operates with individual IPages using IDocumentModel::GetData when calculating a layout and rendering bitmaps. The view also subscribes to IDocumentModelCallback notifications that the model should send when some events occur (e.g. document added/deleted).

There are so-called model 'roles', like in Qt models. This approach helps to represent different parts for one index - the text on top of the page, the page itself and the font for the text. Toolbar role on view's side is not implemented yet, its' purpose is to provide some tool to operate on individual pages.

A generic model implementation is represented by CBasicDocumentModel. It can store IDocuments correctly, caching their IPages to quickly reply on IDocumentModel::GetData, and it also notifies the view on the changes.

CDocumentFromDisk and CWICImage are also two very basic implementations of the IDocument and the IPage respectively for a document that can be loaded from path and is supported by Windows Imaging Component (WIC). Based on them, it is possible to implement any other document type such as PDF, for example (if you have some renderer).

Example

The example application that uses the view as it's child in the main window is implemented in example directory. It includes the view creation and populating it with images from bin and radio buttons to switch between layouts.

Build

The project implementation began on Linux using MinGW to compile and Wine to run, so the CMakeLists.txt is for building on Linux (ccurrently) but later I introduced an MSVC .sln as well. The build system is not mature yet, I will work on that.

Linux

Prerequesties

• MinGW
• Wine

mkdir build; cd build; cmake ../; cmake --build . -- j$(nproc)

The output is the example binary called DocumentViewer.exe and the static library libimageviewer.a. You can run like ./DocumentViewer.exe.

Windows

Prerequesties

• Visual Studio with Windows SDK installed

Just open the solution in Visual Studio and build it. Use the example project to run.