workspace/kwin/clients/plastik/plastikbutton.cpp

   1 /* Plastik KWin window decoration
   2   Copyright (C) 2003-2005 Sandro Giessl <sandro@giessl.com>
   3
   4   based on the window decoration "Web":
   5   Copyright (C) 2001 Rik Hemsley (rikkus) <rik@kde.org>
   6
   7   This program is free software; you can redistribute it and/or
   8   modify it under the terms of the GNU General Public
   9   License as published by the Free Software Foundation; either
  10   version 2 of the License, or (at your option) any later version.
  11
  12   This program is distributed in the hope that it will be useful,
  13   but WITHOUT ANY WARRANTY; without even the implied warranty of
  14   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15   General Public License for more details.
  16
  17   You should have received a copy of the GNU General Public License
  18   along with this program; see the file COPYING.  If not, write to
  19   the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  20   Boston, MA 02110-1301, USA.
  21  */
  22
  23 #include "plastikbutton.h"
  24
  25 // #include <kwin/options.h>
  26
  27 #include <QAbstractButton>
  28 #include <QStyle>
  29 #include <QBitmap>
  30 #include <QPainter>
  31 #include <QPixmap>
  32 #include <QTimer>
  33
  34 #include "plastikbutton.moc"
  35 #include "plastikclient.h"
  36
  37 #include <KGlobalSettings>
  38 #include <KColorScheme>
  39 #include <KColorUtils>
  40
  41 namespace KWinPlastik
  42 {
  43
  44 static const uint TIMERINTERVAL = 50; // msec
  45 static const uint ANIMATIONSTEPS = 4;
  46
  47 PlastikButton::PlastikButton(ButtonType type, PlastikClient *parent)
  48     : KCommonDecorationButton(type, parent),
  49     m_client(parent),
  50     m_iconType(NumButtonIcons),
  51     hover(false)
  52 {
  53     setAttribute(Qt::WA_NoSystemBackground);
  54
  55     // no need to reset here as the button will be reseted on first resize.
  56
  57     animTmr = new QTimer(this);
  58     animTmr->setSingleShot(true);  // single-shot
  59     connect(animTmr, SIGNAL(timeout() ), this, SLOT(animate() ) );
  60     animProgress = 0;
  61 }
  62
  63 PlastikButton::~PlastikButton()
  64 {
  65 }
  66
  67 void PlastikButton::reset(unsigned long changed)
  68 {
  69     if (changed&DecorationReset || changed&ManualReset || changed&SizeChange || changed&StateChange) {
  70         switch (type() ) {
  71             case CloseButton:
  72                 m_iconType = CloseIcon;
  73                 break;
  74             case HelpButton:
  75                 m_iconType = HelpIcon;
  76                 break;
  77             case MinButton:
  78                 m_iconType = MinIcon;
  79                 break;
  80             case MaxButton:
  81                 if (isChecked()) {
  82                     m_iconType = MaxRestoreIcon;
  83                 } else {
  84                     m_iconType = MaxIcon;
  85                 }
  86                 break;
  87             case OnAllDesktopsButton:
  88                 if (isChecked()) {
  89                     m_iconType = NotOnAllDesktopsIcon;
  90                 } else {
  91                     m_iconType = OnAllDesktopsIcon;
  92                 }
  93                 break;
  94             case ShadeButton:
  95                 if (isChecked()) {
  96                     m_iconType = UnShadeIcon;
  97                 } else {
  98                     m_iconType = ShadeIcon;
  99                 }
 100                 break;
 101             case AboveButton:
 102                 if (isChecked()) {
 103                     m_iconType = NoKeepAboveIcon;
 104                 } else {
 105                     m_iconType = KeepAboveIcon;
 106                 }
 107                 break;
 108             case BelowButton:
 109                 if (isChecked()) {
 110                     m_iconType = NoKeepBelowIcon;
 111                 } else {
 112                     m_iconType = KeepBelowIcon;
 113                 }
 114                 break;
 115             default:
 116                 m_iconType = NumButtonIcons; // empty...
 117                 break;
 118         }
 119
 120         this->update();
 121     }
 122 }
 123
 124 void PlastikButton::animate()
 125 {
 126     animTmr->stop();
 127
 128     if(hover) {
 129         if(animProgress < ANIMATIONSTEPS) {
 130             if (Handler()->animateButtons() ) {
 131                 animProgress++;
 132             } else {
 133                 animProgress = ANIMATIONSTEPS;
 134             }
 135             animTmr->start(TIMERINTERVAL); // single-shot timer
 136         }
 137     } else {
 138         if(animProgress > 0) {
 139             if (Handler()->animateButtons() ) {
 140                 animProgress--;
 141             } else {
 142                 animProgress = 0;
 143             }
 144             animTmr->start(TIMERINTERVAL); // single-shot timer
 145         }
 146     }
 147
 148     repaint();
 149 }
 150
 151 void PlastikButton::enterEvent(QEvent *e)
 152 {
 153     QAbstractButton::enterEvent(e);
 154
 155     hover = true;
 156     animate();
 157 }
 158
 159 void PlastikButton::leaveEvent(QEvent *e)
 160 {
 161     QAbstractButton::leaveEvent(e);
 162
 163     hover = false;
 164     animate();
 165 }
 166
 167 void PlastikButton::paintEvent(QPaintEvent *)
 168 {
 169     QPainter p(this);
 170     drawButton(&p);
 171 }
 172
 173 void PlastikButton::drawButton(QPainter *painter)
 174 {
 175     QRect r(0,0,width(),height());
 176
 177     bool active = m_client->isActive();
 178     QPixmap tempPixmap;
 179
 180
 181     double c = KGlobalSettings::contrastF();
 182     QColor titleBar = KDecoration::options()->color(KDecoration::ColorTitleBar, active);
 183     QColor contourTop = KColorScheme::shade(titleBar, KColorScheme::DarkShade, c - 0.4);
 184     QColor contourBottom = KColorScheme::shade(titleBar, KColorScheme::MidShade, c);
 185     QColor surfaceTop = KColorScheme::shade(titleBar, KColorScheme::MidlightShade, c - 0.4);
 186     QColor surfaceBottom = KColorScheme::shade(titleBar, KColorScheme::LightShade, c - 0.4);
 187
 188     QColor highlightColor = titleBar;
 189     double alpha = 0;
 190     if (type() == CloseButton) {
 191         KColorScheme kcs(active ? QPalette::Active : QPalette::Inactive, KColorScheme::Button);
 192         highlightColor = kcs.foreground(KColorScheme::NegativeText).color();
 193     }
 194     if (isDown()) {
 195         highlightColor = KColorScheme::shade(highlightColor, KColorScheme::ShadowShade);
 196         alpha = 0.3;
 197     }
 198     else if (animProgress > 0) {
 199         alpha = 0.6 * (double)animProgress / (double)ANIMATIONSTEPS;
 200         highlightColor = KColorScheme::shade(highlightColor, KColorScheme::LightShade, qMin(1.0, c + 0.4));
 201     }
 202
 203     if (alpha > 0.0) {
 204         contourTop    = KColorUtils::mix(contourTop,    highlightColor, alpha*0.4);
 205         contourBottom = KColorUtils::mix(contourBottom, highlightColor, alpha*0.4);
 206         surfaceTop    = KColorUtils::mix(surfaceTop,    highlightColor, alpha);
 207         surfaceBottom = KColorUtils::mix(surfaceBottom, highlightColor, alpha);
 208     }
 209
 210     QPixmap buffer(width(), height());
 211     QPainter bP(&buffer);
 212
 213     // fake the titlebar background
 214     bP.drawTiledPixmap(0, 0, width(), width(), m_client->getTitleBarTile(active) );
 215
 216     if (type() != MenuButton || hover || animProgress != 0) {
 217         qreal rxo = 600/width();
 218         qreal ryo = 600/height();
 219         qreal rxi = 500/width();
 220         qreal ryi = 500/height();
 221         bP.setPen(Qt::NoPen);
 222         bP.setRenderHints(QPainter::Antialiasing);
 223         // contour
 224         QLinearGradient outlineGradient(0, 0, 0, r.height());
 225         outlineGradient.setColorAt(0.0, contourTop);
 226         outlineGradient.setColorAt(1.0, contourBottom);
 227         bP.setBrush(outlineGradient);
 228         bP.drawRoundRect(r, rxo, ryo);
 229         // surface
 230         QLinearGradient surfaceGradient(0, 0, 0, r.height());
 231         surfaceGradient.setColorAt(0.0, surfaceTop);
 232         surfaceGradient.setColorAt(1.0, surfaceBottom);
 233         bP.setBrush(surfaceGradient);
 234         bP.drawRoundRect(r.adjusted(1,1,-1,-1), rxi, ryi);
 235     }
 236
 237     if (type() == MenuButton)
 238     {
 239         QPixmap menuIcon(m_client->icon().pixmap( style()->pixelMetric( QStyle::PM_SmallIconSize ) ));
 240         if (width() < menuIcon.width() || height() < menuIcon.height() ) {
 241             menuIcon = menuIcon.scaled(width(), height());
 242         }
 243         bP.drawPixmap((width()-menuIcon.width())/2, (height()-menuIcon.height())/2, menuIcon);
 244     }
 245     else
 246     {
 247         int dX,dY;
 248         const QBitmap &icon = Handler()->buttonBitmap(m_iconType, size(), decoration()->isToolWindow() );
 249         dX = r.x()+(r.width()-icon.width())/2;
 250         dY = r.y()+(r.height()-icon.height())/2;
 251         if (isDown() ) {
 252             dY++;
 253         }
 254
 255         QColor fontColor = Handler()->getColor(TitleFont,active);
 256         if(!isDown() && Handler()->titleShadow() ) {
 257             QColor shadowColor = KColorScheme::shade(fontColor, KColorScheme::ShadowShade);
 258             shadowColor.setAlphaF(shadowColor.alphaF() * 0.3);
 259             bP.setPen(shadowColor);
 260             bP.drawPixmap(dX+1, dY+1, icon);
 261         }
 262
 263         bP.setPen(fontColor );
 264         bP.drawPixmap(dX, dY, icon);
 265     }
 266
 267     bP.end();
 268     painter->drawPixmap(0, 0, buffer);
 269 }
 270
 271 QBitmap IconEngine::icon(ButtonIcon icon, int size)
 272 {
 273     if (size%2 == 0)
 274         --size;
 275
 276     QBitmap bitmap(size,size);
 277     bitmap.fill(Qt::color0);
 278     QPainter p(&bitmap);
 279
 280     p.setPen(Qt::color1);
 281
 282     QRect r = bitmap.rect();
 283
 284     // line widths
 285     int lwTitleBar = 1;
 286     if (r.width() > 16) {
 287         lwTitleBar = 4;
 288     } else if (r.width() > 4) {
 289         lwTitleBar = 2;
 290     }
 291     int lwArrow = 1;
 292     if (r.width() > 16) {
 293         lwArrow = 4;
 294     } else if (r.width() > 7) {
 295         lwArrow = 2;
 296     }
 297
 298     switch(icon) {
 299         case CloseIcon:
 300         {
 301             int lineWidth = 1;
 302             if (r.width() > 16) {
 303                 lineWidth = 3;
 304             } else if (r.width() > 4) {
 305                 lineWidth = 2;
 306             }
 307
 308             drawObject(p, DiagonalLine, r.x(), r.y(), r.width(), lineWidth);
 309             drawObject(p, CrossDiagonalLine, r.x(), r.bottom(), r.width(), lineWidth);
 310
 311             break;
 312         }
 313
 314         case MaxIcon:
 315         {
 316             int lineWidth2 = 1; // frame
 317             if (r.width() > 16) {
 318                 lineWidth2 = 2;
 319             } else if (r.width() > 4) {
 320                 lineWidth2 = 1;
 321             }
 322
 323             drawObject(p, HorizontalLine, r.x(), r.top(), r.width(), lwTitleBar);
 324             drawObject(p, HorizontalLine, r.x(), r.bottom()-(lineWidth2-1), r.width(), lineWidth2);
 325             drawObject(p, VerticalLine, r.x(), r.top(), r.height(), lineWidth2);
 326             drawObject(p, VerticalLine, r.right()-(lineWidth2-1), r.top(), r.height(), lineWidth2);
 327
 328             break;
 329         }
 330
 331         case MaxRestoreIcon:
 332         {
 333             int lineWidth2 = 1; // frame
 334             if (r.width() > 16) {
 335                 lineWidth2 = 2;
 336             } else if (r.width() > 4) {
 337                 lineWidth2 = 1;
 338             }
 339
 340             int margin1, margin2;
 341             margin1 = margin2 = lineWidth2*2;
 342             if (r.width() < 8)
 343                 margin1 = 1;
 344
 345             // background window
 346             drawObject(p, HorizontalLine, r.x()+margin1, r.top(), r.width()-margin1, lineWidth2);
 347             drawObject(p, HorizontalLine, r.right()-margin2, r.bottom()-(lineWidth2-1)-margin1, margin2, lineWidth2);
 348             drawObject(p, VerticalLine, r.x()+margin1, r.top(), margin2, lineWidth2);
 349             drawObject(p, VerticalLine, r.right()-(lineWidth2-1), r.top(), r.height()-margin1, lineWidth2);
 350
 351             // foreground window
 352             drawObject(p, HorizontalLine, r.x(), r.top()+margin2, r.width()-margin2, lwTitleBar);
 353             drawObject(p, HorizontalLine, r.x(), r.bottom()-(lineWidth2-1), r.width()-margin2, lineWidth2);
 354             drawObject(p, VerticalLine, r.x(), r.top()+margin2, r.height(), lineWidth2);
 355             drawObject(p, VerticalLine, r.right()-(lineWidth2-1)-margin2, r.top()+margin2, r.height(), lineWidth2);
 356
 357             break;
 358         }
 359
 360         case MinIcon:
 361         {
 362             drawObject(p, HorizontalLine, r.x(), r.bottom()-(lwTitleBar-1), r.width(), lwTitleBar);
 363
 364             break;
 365         }
 366
 367         case HelpIcon:
 368         {
 369             int center = r.x()+r.width()/2 -1;
 370             int side = r.width()/4;
 371
 372             // paint a question mark... code is quite messy, to be cleaned up later...! :o
 373
 374             if (r.width() > 16) {
 375                 int lineWidth = 3;
 376
 377                 // top bar
 378                 drawObject(p, HorizontalLine, center-side+3, r.y(), 2*side-3-1, lineWidth);
 379                 // top bar rounding
 380                 drawObject(p, CrossDiagonalLine, center-side-1, r.y()+5, 6, lineWidth);
 381                 drawObject(p, DiagonalLine, center+side-3, r.y(), 5, lineWidth);
 382                 // right bar
 383                 drawObject(p, VerticalLine, center+side+2-lineWidth, r.y()+3, r.height()-(2*lineWidth+side+2+1), lineWidth);
 384                 // bottom bar
 385                 drawObject(p, CrossDiagonalLine, center, r.bottom()-2*lineWidth, side+2, lineWidth);
 386                 drawObject(p, HorizontalLine, center, r.bottom()-3*lineWidth+2, lineWidth, lineWidth);
 387                 // the dot
 388                 drawObject(p, HorizontalLine, center, r.bottom()-(lineWidth-1), lineWidth, lineWidth);
 389             } else if (r.width() > 8) {
 390                 int lineWidth = 2;
 391
 392                 // top bar
 393                 drawObject(p, HorizontalLine, center-(side-1), r.y(), 2*side-1, lineWidth);
 394                 // top bar rounding
 395                 if (r.width() > 9) {
 396                     drawObject(p, CrossDiagonalLine, center-side-1, r.y()+3, 3, lineWidth);
 397                 } else {
 398                     drawObject(p, CrossDiagonalLine, center-side-1, r.y()+2, 3, lineWidth);
 399                 }
 400                 drawObject(p, DiagonalLine, center+side-1, r.y(), 3, lineWidth);
 401                 // right bar
 402                 drawObject(p, VerticalLine, center+side+2-lineWidth, r.y()+2, r.height()-(2*lineWidth+side+1), lineWidth);
 403                 // bottom bar
 404                 drawObject(p, CrossDiagonalLine, center, r.bottom()-2*lineWidth+1, side+2, lineWidth);
 405                 // the dot
 406                 drawObject(p, HorizontalLine, center, r.bottom()-(lineWidth-1), lineWidth, lineWidth);
 407             } else {
 408                 int lineWidth = 1;
 409
 410                 // top bar
 411                 drawObject(p, HorizontalLine, center-(side-1), r.y(), 2*side, lineWidth);
 412                 // top bar rounding
 413                 drawObject(p, CrossDiagonalLine, center-side-1, r.y()+1, 2, lineWidth);
 414                 // right bar
 415                 drawObject(p, VerticalLine, center+side+1, r.y(), r.height()-(side+2+1), lineWidth);
 416                 // bottom bar
 417                 drawObject(p, CrossDiagonalLine, center, r.bottom()-2, side+2, lineWidth);
 418                 // the dot
 419                 drawObject(p, HorizontalLine, center, r.bottom(), 1, 1);
 420             }
 421
 422             break;
 423         }
 424
 425         case NotOnAllDesktopsIcon:
 426         {
 427             int lwMark = r.width()-lwTitleBar*2-2;
 428             if (lwMark < 1)
 429                 lwMark = 3;
 430
 431             drawObject(p, HorizontalLine, r.x()+(r.width()-lwMark)/2, r.y()+(r.height()-lwMark)/2, lwMark, lwMark);
 432
 433             // Fall through to OnAllDesktopsIcon intended!
 434         }
 435         case OnAllDesktopsIcon:
 436         {
 437             // horizontal bars
 438             drawObject(p, HorizontalLine, r.x()+lwTitleBar, r.y(), r.width()-2*lwTitleBar, lwTitleBar);
 439             drawObject(p, HorizontalLine, r.x()+lwTitleBar, r.bottom()-(lwTitleBar-1), r.width()-2*lwTitleBar, lwTitleBar);
 440             // vertical bars
 441             drawObject(p, VerticalLine, r.x(), r.y()+lwTitleBar, r.height()-2*lwTitleBar, lwTitleBar);
 442             drawObject(p, VerticalLine, r.right()-(lwTitleBar-1), r.y()+lwTitleBar, r.height()-2*lwTitleBar, lwTitleBar);
 443
 444
 445             break;
 446         }
 447
 448         case NoKeepAboveIcon:
 449         {
 450             int center = r.x()+r.width()/2;
 451
 452             // arrow
 453             drawObject(p, CrossDiagonalLine, r.x(), center+2*lwArrow, center-r.x(), lwArrow);
 454             drawObject(p, DiagonalLine, r.x()+center, r.y()+1+2*lwArrow, center-r.x(), lwArrow);
 455             if (lwArrow>1)
 456                 drawObject(p, HorizontalLine, center-(lwArrow-2), r.y()+2*lwArrow, (lwArrow-2)*2, lwArrow);
 457
 458             // Fall through to KeepAboveIcon intended!
 459         }
 460         case KeepAboveIcon:
 461         {
 462             int center = r.x()+r.width()/2;
 463
 464             // arrow
 465             drawObject(p, CrossDiagonalLine, r.x(), center, center-r.x(), lwArrow);
 466             drawObject(p, DiagonalLine, r.x()+center, r.y()+1, center-r.x(), lwArrow);
 467             if (lwArrow>1)
 468                 drawObject(p, HorizontalLine, center-(lwArrow-2), r.y(), (lwArrow-2)*2, lwArrow);
 469
 470             break;
 471         }
 472
 473         case NoKeepBelowIcon:
 474         {
 475             int center = r.x()+r.width()/2;
 476
 477             // arrow
 478             drawObject(p, DiagonalLine, r.x(), center-2*lwArrow, center-r.x(), lwArrow);
 479             drawObject(p, CrossDiagonalLine, r.x()+center, r.bottom()-1-2*lwArrow, center-r.x(), lwArrow);
 480             if (lwArrow>1)
 481                 drawObject(p, HorizontalLine, center-(lwArrow-2), r.bottom()-(lwArrow-1)-2*lwArrow, (lwArrow-2)*2, lwArrow);
 482
 483             // Fall through to KeepBelowIcon intended!
 484         }
 485         case KeepBelowIcon:
 486         {
 487             int center = r.x()+r.width()/2;
 488
 489             // arrow
 490             drawObject(p, DiagonalLine, r.x(), center, center-r.x(), lwArrow);
 491             drawObject(p, CrossDiagonalLine, r.x()+center, r.bottom()-1, center-r.x(), lwArrow);
 492             if (lwArrow>1)
 493                 drawObject(p, HorizontalLine, center-(lwArrow-2), r.bottom()-(lwArrow-1), (lwArrow-2)*2, lwArrow);
 494
 495             break;
 496         }
 497
 498         case ShadeIcon:
 499         {
 500             drawObject(p, HorizontalLine, r.x(), r.y(), r.width(), lwTitleBar);
 501
 502             break;
 503         }
 504
 505         case UnShadeIcon:
 506         {
 507             int lw1 = 1;
 508             int lw2 = 1;
 509             if (r.width() > 16) {
 510                 lw1 = 4;
 511                 lw2 = 2;
 512             } else if (r.width() > 7) {
 513                 lw1 = 2;
 514                 lw2 = 1;
 515             }
 516
 517             int h = qMax( (r.width()/2), (lw1+2*lw2) );
 518
 519             // horizontal bars
 520             drawObject(p, HorizontalLine, r.x(), r.y(), r.width(), lw1);
 521             drawObject(p, HorizontalLine, r.x(), r.x()+h-(lw2-1), r.width(), lw2);
 522             // vertical bars
 523             drawObject(p, VerticalLine, r.x(), r.y(), h, lw2);
 524             drawObject(p, VerticalLine, r.right()-(lw2-1), r.y(), h, lw2);
 525
 526             break;
 527         }
 528
 529         default:
 530             break;
 531     }
 532
 533     p.end();
 534
 535     bitmap.setMask(bitmap);
 536
 537     return bitmap;
 538 }
 539
 540 void IconEngine::drawObject(QPainter &p, Object object, int x, int y, int length, int lineWidth)
 541 {
 542     switch(object) {
 543         case DiagonalLine:
 544             if (lineWidth <= 1) {
 545                 for (int i = 0; i < length; ++i) {
 546                     p.drawPoint(x+i,y+i);
 547                 }
 548             } else if (lineWidth <= 2) {
 549                 for (int i = 0; i < length; ++i) {
 550                     p.drawPoint(x+i,y+i);
 551                 }
 552                 for (int i = 0; i < (length-1); ++i) {
 553                     p.drawPoint(x+1+i,y+i);
 554                     p.drawPoint(x+i,y+1+i);
 555                 }
 556             } else {
 557                 for (int i = 1; i < (length-1); ++i) {
 558                     p.drawPoint(x+i,y+i);
 559                 }
 560                 for (int i = 0; i < (length-1); ++i) {
 561                     p.drawPoint(x+1+i,y+i);
 562                     p.drawPoint(x+i,y+1+i);
 563                 }
 564                 for (int i = 0; i < (length-2); ++i) {
 565                     p.drawPoint(x+2+i,y+i);
 566                     p.drawPoint(x+i,y+2+i);
 567                 }
 568             }
 569             break;
 570         case CrossDiagonalLine:
 571             if (lineWidth <= 1) {
 572                 for (int i = 0; i < length; ++i) {
 573                     p.drawPoint(x+i,y-i);
 574                 }
 575             } else if (lineWidth <= 2) {
 576                 for (int i = 0; i < length; ++i) {
 577                     p.drawPoint(x+i,y-i);
 578                 }
 579                 for (int i = 0; i < (length-1); ++i) {
 580                     p.drawPoint(x+1+i,y-i);
 581                     p.drawPoint(x+i,y-1-i);
 582                 }
 583             } else {
 584                 for (int i = 1; i < (length-1); ++i) {
 585                     p.drawPoint(x+i,y-i);
 586                 }
 587                 for (int i = 0; i < (length-1); ++i) {
 588                     p.drawPoint(x+1+i,y-i);
 589                     p.drawPoint(x+i,y-1-i);
 590                 }
 591                 for (int i = 0; i < (length-2); ++i) {
 592                     p.drawPoint(x+2+i,y-i);
 593                     p.drawPoint(x+i,y-2-i);
 594                 }
 595             }
 596             break;
 597         case HorizontalLine:
 598             for (int i = 0; i < lineWidth; ++i) {
 599                 p.drawLine(x,y+i, x+length-1, y+i);
 600             }
 601             break;
 602         case VerticalLine:
 603             for (int i = 0; i < lineWidth; ++i) {
 604                 p.drawLine(x+i,y, x+i, y+length-1);
 605             }
 606             break;
 607         default:
 608             break;
 609     }
 610 }
 611
 612 } // KWinPlastik