/**
 * @file llresizebar.cpp
 * @brief LLResizeBar base class
 *
 * $LicenseInfo:firstyear=2001&license=viewerlgpl$
 * Second Life Viewer Source Code
 * Copyright (C) 2010, Linden Research, Inc.
 *
 * This library 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;
 * version 2.1 of the License only.
 *
 * This library 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 this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 *
 * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
 * $/LicenseInfo$
 */

#include "linden_common.h"

#include "llresizebar.h"

#include "lllocalcliprect.h"
#include "llmath.h"
#include "llui.h"
#include "llmenugl.h"
#include "llfocusmgr.h"
#include "llwindow.h"

LLResizeBar::Params::Params()
:   max_size("max_size", S32_MAX),
    snapping_enabled("snapping_enabled", true),
    resizing_view("resizing_view"),
    side("side"),
    allow_double_click_snapping("allow_double_click_snapping", true)
{
    name = "resize_bar";
}

LLResizeBar::LLResizeBar(const LLResizeBar::Params& p)
:   LLView(p),
    mDragLastScreenX( 0 ),
    mDragLastScreenY( 0 ),
    mLastMouseScreenX( 0 ),
    mLastMouseScreenY( 0 ),
    mMinSize( p.min_size ),
    mMaxSize( p.max_size ),
    mSide( p.side ),
    mSnappingEnabled(p.snapping_enabled),
    mAllowDoubleClickSnapping(p.allow_double_click_snapping),
    mResizingView(p.resizing_view),
    mResizeListener(NULL),
    mImagePanel(NULL)
{
    setFollowsNone();
    // set up some generically good follow code.
    switch( mSide )
    {
    case LEFT:
        setFollowsLeft();
        setFollowsTop();
        setFollowsBottom();
        break;
    case TOP:
        setFollowsTop();
        setFollowsLeft();
        setFollowsRight();
        break;
    case RIGHT:
        setFollowsRight();
        setFollowsTop();
        setFollowsBottom();
        break;
    case BOTTOM:
        setFollowsBottom();
        setFollowsLeft();
        setFollowsRight();
        break;
    default:
        break;
    }
}

bool LLResizeBar::handleMouseDown(S32 x, S32 y, MASK mask)
{
    if (!canResize()) return false;

    // Route future Mouse messages here preemptively.  (Release on mouse up.)
    // No handler needed for focus lost since this clas has no state that depends on it.
    gFocusMgr.setMouseCapture( this );

    localPointToScreen(x, y, &mDragLastScreenX, &mDragLastScreenY);
    mLastMouseScreenX = mDragLastScreenX;
    mLastMouseScreenY = mDragLastScreenY;

    return true;
}


bool LLResizeBar::handleMouseUp(S32 x, S32 y, MASK mask)
{
    bool    handled = false;

    if( hasMouseCapture() )
    {
        // Release the mouse
        gFocusMgr.setMouseCapture( NULL );
        handled = true;
    }
    else
    {
        handled = true;
    }
    return handled;
}


bool LLResizeBar::handleHover(S32 x, S32 y, MASK mask)
{
    bool    handled = false;

    // We only handle the click if the click both started and ended within us
    if( hasMouseCapture() )
    {
        S32 screen_x;
        S32 screen_y;
        localPointToScreen(x, y, &screen_x, &screen_y);

        S32 delta_x = screen_x - mDragLastScreenX;
        S32 delta_y = screen_y - mDragLastScreenY;

        LLCoordGL mouse_dir;
        // use hysteresis on mouse motion to preserve user intent when mouse stops moving
        mouse_dir.mX = (screen_x == mLastMouseScreenX) ? mLastMouseDir.mX : screen_x - mLastMouseScreenX;
        mouse_dir.mY = (screen_y == mLastMouseScreenY) ? mLastMouseDir.mY : screen_y - mLastMouseScreenY;
        mLastMouseDir = mouse_dir;
        mLastMouseScreenX = screen_x;
        mLastMouseScreenY = screen_y;

        // Make sure the mouse in still over the application.  We don't want to make the parent
        // so big that we can't see the resize handle any more.
        LLRect valid_rect = getRootView()->getRect();

        if( valid_rect.localPointInRect( screen_x, screen_y ) && mResizingView )
        {
            // Resize the parent
            LLRect orig_rect = mResizingView->getRect();
            LLRect scaled_rect = orig_rect;

            S32 new_width = orig_rect.getWidth();
            S32 new_height = orig_rect.getHeight();

            switch( mSide )
            {
            case LEFT:
                new_width = llclamp(orig_rect.getWidth() - delta_x, mMinSize, mMaxSize);
                delta_x = orig_rect.getWidth() - new_width;
                scaled_rect.translate(delta_x, 0);
                break;

            case TOP:
                new_height = llclamp(orig_rect.getHeight() + delta_y, mMinSize, mMaxSize);
                delta_y = new_height - orig_rect.getHeight();
                break;

            case RIGHT:
                new_width = llclamp(orig_rect.getWidth() + delta_x, mMinSize, mMaxSize);
                delta_x = new_width - orig_rect.getWidth();
                break;

            case BOTTOM:
                new_height = llclamp(orig_rect.getHeight() - delta_y, mMinSize, mMaxSize);
                delta_y = orig_rect.getHeight() - new_height;
                scaled_rect.translate(0, delta_y);
                break;
            }

            notifyParent(LLSD().with("action", "resize")
                .with("view_name", mResizingView->getName())
                .with("new_height", new_height)
                .with("new_width", new_width));

            scaled_rect.mTop = scaled_rect.mBottom + new_height;
            scaled_rect.mRight = scaled_rect.mLeft + new_width;
            mResizingView->setRect(scaled_rect);

            LLView* snap_view = NULL;

            if (mSnappingEnabled)
            {
                static LLUICachedControl<S32> snap_margin ("SnapMargin", 0);
                switch( mSide )
                {
                case LEFT:
                    snap_view = mResizingView->findSnapEdge(scaled_rect.mLeft, mouse_dir, SNAP_LEFT, SNAP_PARENT_AND_SIBLINGS, snap_margin);
                    break;
                case TOP:
                    snap_view = mResizingView->findSnapEdge(scaled_rect.mTop, mouse_dir, SNAP_TOP, SNAP_PARENT_AND_SIBLINGS, snap_margin);
                    break;
                case RIGHT:
                    snap_view = mResizingView->findSnapEdge(scaled_rect.mRight, mouse_dir, SNAP_RIGHT, SNAP_PARENT_AND_SIBLINGS, snap_margin);
                    break;
                case BOTTOM:
                    snap_view = mResizingView->findSnapEdge(scaled_rect.mBottom, mouse_dir, SNAP_BOTTOM, SNAP_PARENT_AND_SIBLINGS, snap_margin);
                    break;
                }
            }

            // register "snap" behavior with snapped view
            mResizingView->setSnappedTo(snap_view);

            // restore original rectangle so the appropriate changes are detected
            mResizingView->setRect(orig_rect);
            // change view shape as user operation
            mResizingView->setShape(scaled_rect, true);

            // update last valid mouse cursor position based on resized view's actual size
            LLRect new_rect = mResizingView->getRect();

            switch(mSide)
            {
            case LEFT:
            {
                S32 actual_delta_x = new_rect.mLeft - orig_rect.mLeft;
                if (actual_delta_x != delta_x)
                {
                    // restore everything by left
                    new_rect.mBottom = orig_rect.mBottom;
                    new_rect.mTop = orig_rect.mTop;
                    new_rect.mRight = orig_rect.mRight;
                    mResizingView->setShape(new_rect, true);
                }
                mDragLastScreenX += actual_delta_x;

                break;
            }
            case RIGHT:
            {
                S32 actual_delta_x = new_rect.mRight - orig_rect.mRight;
                if (actual_delta_x != delta_x)
                {
                    // restore everything by left
                    new_rect.mBottom = orig_rect.mBottom;
                    new_rect.mTop = orig_rect.mTop;
                    new_rect.mLeft = orig_rect.mLeft;
                    mResizingView->setShape(new_rect, true);
                }
                mDragLastScreenX += new_rect.mRight - orig_rect.mRight;
                break;
            }
            case TOP:
            {
                S32 actual_delta_y = new_rect.mTop - orig_rect.mTop;
                if (actual_delta_y != delta_y)
                {
                    // restore everything by left
                    new_rect.mBottom = orig_rect.mBottom;
                    new_rect.mLeft = orig_rect.mLeft;
                    new_rect.mRight = orig_rect.mRight;
                    mResizingView->setShape(new_rect, true);
                }
                mDragLastScreenY += new_rect.mTop - orig_rect.mTop;
                break;
            }
            case BOTTOM:
            {
                S32 actual_delta_y = new_rect.mBottom - orig_rect.mBottom;
                if (actual_delta_y != delta_y)
                {
                    // restore everything by left
                    new_rect.mTop = orig_rect.mTop;
                    new_rect.mLeft = orig_rect.mLeft;
                    new_rect.mRight = orig_rect.mRight;
                    mResizingView->setShape(new_rect, true);
                }
                mDragLastScreenY += new_rect.mBottom- orig_rect.mBottom;
                break;
            }
            default:
                break;
            }
        }

        handled = true;
    }
    else
    {
        handled = true;
    }

    if( handled && canResize() )
    {
        switch( mSide )
        {
        case LEFT:
        case RIGHT:
            getWindow()->setCursor(UI_CURSOR_SIZEWE);
            break;

        case TOP:
        case BOTTOM:
            getWindow()->setCursor(UI_CURSOR_SIZENS);
            break;
        }
    }

    if (mResizeListener)
    {
        mResizeListener(NULL);
    }

    return handled;
} // end LLResizeBar::handleHover

bool LLResizeBar::handleDoubleClick(S32 x, S32 y, MASK mask)
{
    LLRect orig_rect = mResizingView->getRect();
    LLRect scaled_rect = orig_rect;

    if (mSnappingEnabled && mAllowDoubleClickSnapping)
    {
        switch( mSide )
        {
        case LEFT:
            mResizingView->findSnapEdge(scaled_rect.mLeft, LLCoordGL(0, 0), SNAP_LEFT, SNAP_PARENT_AND_SIBLINGS, S32_MAX);
            scaled_rect.mLeft = scaled_rect.mRight - llclamp(scaled_rect.getWidth(), mMinSize, mMaxSize);
            break;
        case TOP:
            mResizingView->findSnapEdge(scaled_rect.mTop, LLCoordGL(0, 0), SNAP_TOP, SNAP_PARENT_AND_SIBLINGS, S32_MAX);
            scaled_rect.mTop = scaled_rect.mBottom + llclamp(scaled_rect.getHeight(), mMinSize, mMaxSize);
            break;
        case RIGHT:
            mResizingView->findSnapEdge(scaled_rect.mRight, LLCoordGL(0, 0), SNAP_RIGHT, SNAP_PARENT_AND_SIBLINGS, S32_MAX);
            scaled_rect.mRight = scaled_rect.mLeft + llclamp(scaled_rect.getWidth(), mMinSize, mMaxSize);
            break;
        case BOTTOM:
            mResizingView->findSnapEdge(scaled_rect.mBottom, LLCoordGL(0, 0), SNAP_BOTTOM, SNAP_PARENT_AND_SIBLINGS, S32_MAX);
            scaled_rect.mBottom = scaled_rect.mTop - llclamp(scaled_rect.getHeight(), mMinSize, mMaxSize);
            break;
        }

        mResizingView->setShape(scaled_rect, true);
    }

    return true;
}

void LLResizeBar::setImagePanel(LLPanel * panelp)
{
    const LLView::child_list_t * children = getChildList();
    if (getChildCount() == 2)
    {
        LLPanel * image_panelp = dynamic_cast<LLPanel*>(children->back());
        if (image_panelp)
        {
            removeChild(image_panelp);
            delete image_panelp;
        }
    }

    addChild(panelp);
    sendChildToBack(panelp);
}

LLPanel * LLResizeBar::getImagePanel() const
{
    return getChildCount() > 0 ? (LLPanel *)getChildList()->back() : NULL;
}