mpv/video/out/win32/droptarget.c

/*
 * This file is part of mpv.
 *
 * mpv is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * mpv is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with mpv.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <windows.h>
#include <ole2.h>
#include <shobjidl.h>

#include "common/msg.h"
#include "common/common.h"
#include "input/input.h"
#include "input/event.h"
#include "osdep/atomic.h"
#include "osdep/io.h"
#include "mpv_talloc.h"

#include "droptarget.h"

typedef struct tagDropTarget {
    IDropTarget iface;
    atomic_int refCnt;
    DWORD lastEffect;
    IDataObject* dataObj;
    struct mp_log *log;
    struct input_ctx *input_ctx;
} DropTarget;

static FORMATETC fmtetc_file = { CF_HDROP, 0, DVASPECT_CONTENT, -1, TYMED_HGLOBAL };
static FORMATETC fmtetc_url = { 0, NULL, DVASPECT_CONTENT, -1, TYMED_HGLOBAL };

static void DropTarget_Destroy(DropTarget* This)
{
    if (This->dataObj != NULL) {
        This->dataObj->lpVtbl->Release(This->dataObj);
        This->dataObj->lpVtbl = NULL;
    }

    talloc_free(This);
}

static HRESULT STDMETHODCALLTYPE DropTarget_QueryInterface(IDropTarget* This,
                                                           REFIID riid,
                                                           void** ppvObject)
{
    if (!IsEqualGUID(riid, &IID_IUnknown) ||
        !IsEqualGUID(riid, &IID_IDataObject)) {
        *ppvObject = NULL;
        return E_NOINTERFACE;
    }

    *ppvObject = This;
    This->lpVtbl->AddRef(This);
    return S_OK;
}

static ULONG STDMETHODCALLTYPE DropTarget_AddRef(IDropTarget* This)
{
    DropTarget* t = (DropTarget*)This;
    return atomic_fetch_add(&t->refCnt, 1) + 1;
}

static ULONG STDMETHODCALLTYPE DropTarget_Release(IDropTarget* This)
{
    DropTarget* t = (DropTarget*)This;
    ULONG cRef = atomic_fetch_add(&t->refCnt, -1) - 1;

    if (cRef == 0) {
        DropTarget_Destroy(t);
    }

    return cRef;
}

static HRESULT STDMETHODCALLTYPE DropTarget_DragEnter(IDropTarget* This,
                                                      IDataObject* pDataObj,
                                                      DWORD grfKeyState,
                                                      POINTL pt,
                                                      DWORD* pdwEffect)
{
    DropTarget* t = (DropTarget*)This;

    pDataObj->lpVtbl->AddRef(pDataObj);
    if (pDataObj->lpVtbl->QueryGetData(pDataObj, &fmtetc_file) != S_OK &&
        pDataObj->lpVtbl->QueryGetData(pDataObj, &fmtetc_url) != S_OK) {

        *pdwEffect = DROPEFFECT_NONE;
    }

    if (t->dataObj != NULL) {
        t->dataObj->lpVtbl->Release(t->dataObj);
    }

    t->dataObj = pDataObj;
    t->lastEffect = *pdwEffect;
    return S_OK;
}

static HRESULT STDMETHODCALLTYPE DropTarget_DragOver(IDropTarget* This,
                                                     DWORD grfKeyState,
                                                     POINTL pt,
                                                     DWORD* pdwEffect)
{
    DropTarget* t = (DropTarget*)This;

    *pdwEffect = t->lastEffect;
    return S_OK;
}

static HRESULT STDMETHODCALLTYPE DropTarget_DragLeave(IDropTarget* This)
{
    DropTarget* t = (DropTarget*)This;

    if (t->dataObj != NULL) {
        t->dataObj->lpVtbl->Release(t->dataObj);
        t->dataObj = NULL;
    }

    return S_OK;
}

static HRESULT STDMETHODCALLTYPE DropTarget_Drop(IDropTarget* This,
                                                 IDataObject* pDataObj,
                                                 DWORD grfKeyState, POINTL pt,
                                                 DWORD* pdwEffect)
{
    DropTarget* t = (DropTarget*)This;

    STGMEDIUM medium;

    if (t->dataObj != NULL) {
        t->dataObj->lpVtbl->Release(t->dataObj);
        t->dataObj = NULL;
    }

    enum mp_dnd_action action = (grfKeyState & MK_SHIFT) ? DND_APPEND : DND_REPLACE;

    pDataObj->lpVtbl->AddRef(pDataObj);

    if (pDataObj->lpVtbl->GetData(pDataObj, &fmtetc_file, &medium) == S_OK) {
        if (GlobalLock(medium.hGlobal) != NULL) {
            HDROP hDrop = (HDROP)medium.hGlobal;

            UINT numFiles = DragQueryFileW(hDrop, 0xFFFFFFFF, NULL, 0);
            char** files = talloc_zero_array(NULL, char*, numFiles);

            UINT nrecvd_files = 0;
            for (UINT i = 0; i < numFiles; i++) {
                UINT len = DragQueryFileW(hDrop, i, NULL, 0);
                wchar_t* buf = talloc_array(NULL, wchar_t, len + 1);

                if (DragQueryFileW(hDrop, i, buf, len + 1) == len) {
                    char* fname = mp_to_utf8(files, buf);
                    files[nrecvd_files++] = fname;

                    MP_VERBOSE(t, "received dropped file: %s\n", fname);
                } else {
                    MP_ERR(t, "error getting dropped file name\n");
                }

                talloc_free(buf);
            }

            GlobalUnlock(medium.hGlobal);
            mp_event_drop_files(t->input_ctx, nrecvd_files, files,
                                action);

            talloc_free(files);
        }

        ReleaseStgMedium(&medium);
    } else if (pDataObj->lpVtbl->GetData(pDataObj,
                                         &fmtetc_url, &medium) == S_OK) {
        // get the URL encoded in US-ASCII
        wchar_t* wurl = GlobalLock(medium.hGlobal);
        if (wurl != NULL) {
            char *url = mp_to_utf8(NULL, wurl);
            if (mp_event_drop_mime_data(t->input_ctx, "text/uri-list",
                                        bstr0(url), action) > 0) {
                MP_VERBOSE(t, "received dropped URL: %s\n", url);
            } else {
                MP_ERR(t, "error getting dropped URL\n");
            }

            talloc_free(url);
            GlobalUnlock(medium.hGlobal);
        }

        ReleaseStgMedium(&medium);
    }
    else {
        t->lastEffect = DROPEFFECT_NONE;
    }

    pDataObj->lpVtbl->Release(pDataObj);
    *pdwEffect = t->lastEffect;
    return S_OK;
}

IDropTarget *mp_w32_droptarget_create(struct mp_log *log,
                                      struct input_ctx *input_ctx)
{
    DropTarget* dropTarget = talloc(NULL, DropTarget);
    IDropTargetVtbl* vtbl = talloc(dropTarget, IDropTargetVtbl);
    *vtbl = (IDropTargetVtbl){
        DropTarget_QueryInterface, DropTarget_AddRef, DropTarget_Release,
        DropTarget_DragEnter, DropTarget_DragOver, DropTarget_DragLeave,
        DropTarget_Drop
    };

    fmtetc_url.cfFormat = (CLIPFORMAT)RegisterClipboardFormat(TEXT("UniformResourceLocatorW"));

    dropTarget->iface.lpVtbl = vtbl;
    atomic_store(&dropTarget->refCnt, 0);
    dropTarget->lastEffect = 0;
    dropTarget->dataObj = NULL;
    dropTarget->log = mp_log_new(dropTarget, log, "droptarget");
    dropTarget->input_ctx = input_ctx;

    return &dropTarget->iface;
}