android.text.Layout#getLineBottom ( )源码实例Demo

private BetterLinkMovementExtended.ClickableSpanWithText findClickableSpanUnderTouch(TextView textView, Spannable text, MotionEvent event) {
    int touchX = (int) event.getX();
    int touchY = (int) event.getY();
    touchX -= textView.getTotalPaddingLeft();
    touchY -= textView.getTotalPaddingTop();
    touchX += textView.getScrollX();
    touchY += textView.getScrollY();
    Layout layout = textView.getLayout();
    int touchedLine = layout.getLineForVertical(touchY);
    int touchOffset = layout.getOffsetForHorizontal(touchedLine, (float) touchX);
    this.touchedLineBounds.left = layout.getLineLeft(touchedLine);
    this.touchedLineBounds.top = (float) layout.getLineTop(touchedLine);
    this.touchedLineBounds.right = layout.getLineWidth(touchedLine) + this.touchedLineBounds.left;
    this.touchedLineBounds.bottom = (float) layout.getLineBottom(touchedLine);
    if (this.touchedLineBounds.contains((float) touchX, (float) touchY)) {
        Object[] spans = text.getSpans(touchOffset, touchOffset, SPAN_CLASS);
        for (Object span : spans) {
            if (span instanceof ClickableSpan) {
                return ClickableSpanWithText.ofSpan(textView, (ClickableSpan) span);
            }
        }
        return null;
    } else {
        return null;
    }
}
 

@Override
protected void onDraw(Canvas canvas) {
	int height = getHeight();
	Layout layout = getLayout();
	int maxHeight = 0;
	for (int i = 0; i < layout.getLineCount(); i++) {
		int bottom = layout.getLineBottom(i);
		if (bottom > height) {
			maxHeight = layout.getLineTop(i);
			break;
		}
	}
	if (maxHeight > 0) {
		canvas.save();
		canvas.clipRect(0, 0, getWidth(), maxHeight);
	}
	super.onDraw(canvas);
	OverlineSpan.draw(this, canvas);
	if (maxHeight > 0) {
		canvas.restore();
	}
}
 

/**
 * Gets the span that was touched.
 * @param tv {@link TextView}
 * @param span {@link Spannable}
 * @param e {@link MotionEvent}
 * @return {@link TouchableSpan}
 */
private TouchableSpan getTouchedSpan(TextView tv, Spannable span, MotionEvent e) {
    // Find the location in which the touch was made
    int x = (int)e.getX();
    int y = (int)e.getY();

    // Ignore padding
    x -= tv.getTotalPaddingLeft();
    y -= tv.getTotalPaddingTop();

    // Account for scrollable text
    x += tv.getScrollX();
    y += tv.getScrollY();

    final Layout layout = tv.getLayout();
    final int touchedLine = layout.getLineForVertical(y);
    final int touchOffset = layout.getOffsetForHorizontal(touchedLine, x);

    // Set bounds of the touched line
    touchBounds.left = layout.getLineLeft(touchedLine);
    touchBounds.top = layout.getLineTop(touchedLine);
    touchBounds.right = layout.getLineRight(touchedLine);
    touchBounds.bottom = layout.getLineBottom(touchedLine);

    // Ensure the span falls within the bounds of the touch
    TouchableSpan touchSpan = null;
    if (touchBounds.contains(x, y)) {
        // Find clickable spans that lie under the touched area
        TouchableSpan[] spans = span.getSpans(touchOffset, touchOffset, TouchableSpan.class);
        touchSpan = (spans.length > 0) ? spans[0] : null;
    }

    return touchSpan;
}
 

private static float getLineBottomWithoutSpacing(@NonNull Layout layout, int line) {
    final float value = layout.getLineBottom(line);

    final boolean isLastLineSpacingNotAdded = Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT;
    final boolean isLastLine = line == (layout.getLineCount() - 1);

    final float lineBottomWithoutSpacing;

    final float lineSpacingExtra = layout.getSpacingAdd();
    final float lineSpacingMultiplier = layout.getSpacingMultiplier();

    final boolean hasLineSpacing = Float.compare(lineSpacingExtra, .0F) != 0
            || Float.compare(lineSpacingMultiplier, 1F) != 0;

    if (!hasLineSpacing || isLastLine && isLastLineSpacingNotAdded) {
        lineBottomWithoutSpacing = value;
    } else {
        final float extra;
        if (Float.compare(lineSpacingMultiplier, 1F) != 0) {
            final float lineHeight = getLineHeight(layout, line);
            extra = lineHeight - (lineHeight - lineSpacingExtra) / lineSpacingMultiplier;
        } else {
            extra = lineSpacingExtra;
        }
        lineBottomWithoutSpacing = value - extra;
    }

    return lineBottomWithoutSpacing;
}
 

@Override
public void onDraw(@NonNull Canvas canvas) {
    if (!isInEditMode()) {
        int top;
        Layout layout = getLayout();
        if (layout != null && codeEditor != null && mHighlightCurrentLine) {
            int currentLineStart = codeEditor.getLineForIndex(getSelectionStart());
            if (currentLineStart == codeEditor.getLineForIndex(getSelectionEnd())) {
                int selectedLineStartIndex = codeEditor.getIndexForStartOfLine(currentLineStart);
                int selectedLineEndIndex = codeEditor.getIndexForEndOfLine(currentLineStart);
                int topVisualLine = layout.getLineForOffset(selectedLineStartIndex);
                int bottomVisualLine = layout.getLineForOffset(selectedLineEndIndex);
                int left = mGutterWidth;
                if (!mShowLineNumbers)
                    left = 0; //убираем отступ для Paint'а если номера строк выключены
                top = layout.getLineTop(topVisualLine) + getPaddingTop();
                int right = (layout.getWidth() + getPaddingLeft()) + getPaddingRight();
                int bottom = layout.getLineBottom(bottomVisualLine) + getPaddingTop();
                canvas.drawRect(left, top, right, bottom, mSelectedLinePaint);
            }
        }
        super.onDraw(canvas);
        if (layout != null && mShowLineNumbers) {
            int prevLineNumber = -1;
            canvas.drawRect(getScrollX(), getScrollY(),
                    mGutterWidth + getScrollX(),
                    getScrollY() + getHeight(), mGutterBackgroundPaint);
            int paddingTop = getPaddingTop();
            int max = mLineUtils.getBottomVisibleLine(this);
            int textRight = (mGutterWidth - mIdealMargin / 2) + getScrollX();
            if (codeEditor != null) {
                int i = mLineUtils.getTopVisibleLine(this);
                if (i >= 2) {
                    i -= 2;
                } else {
                    i = 0;
                }
                while (i <= max) {
                    int number = codeEditor.getLineForIndex(getLayout().getLineStart(i));
                    if (number != prevLineNumber) {
                        canvas.drawText(Integer.toString(number + 1), textRight,
                                layout.getLineBaseline(i) + paddingTop, mLineNumberPaint);
                    }
                    prevLineNumber = number;
                    i++;
                }
                top = getScrollY();
                canvas.drawLine(mGutterWidth + getScrollX(), top,
                        mGutterWidth + getScrollX(), top + getHeight(), mLinePaint);
            }
        }
    }
}
 

public static int getLineBottomWithoutPaddingAndSpacing(
        @NonNull Layout layout,
        int line
) {

    final int bottom = layout.getLineBottom(line);
    final boolean lastLineSpacingNotAdded = Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT;
    final boolean isSpanLastLine = line == (layout.getLineCount() - 1);

    final int lineBottom;
    final float lineSpacingExtra = layout.getSpacingAdd();
    final float lineSpacingMultiplier = layout.getSpacingMultiplier();

    // simplified check
    final boolean hasLineSpacing = lineSpacingExtra != DEFAULT_EXTRA
            || lineSpacingMultiplier != DEFAULT_MULTIPLIER;

    if (!hasLineSpacing
            || (isSpanLastLine && lastLineSpacingNotAdded)) {
        lineBottom = bottom;
    } else {
        final float extra;
        if (Float.compare(DEFAULT_MULTIPLIER, lineSpacingMultiplier) != 0) {
            final int lineHeight = getLineHeight(layout, line);
            extra = lineHeight -
                    ((lineHeight - lineSpacingExtra) / lineSpacingMultiplier);
        } else {
            extra = lineSpacingExtra;
        }
        lineBottom = (int) (bottom - extra + .5F);
    }

    // check if it is the last line that span is occupying **and** that this line is the last
    //  one in TextView
    if (isSpanLastLine
            && (line == layout.getLineCount() - 1)) {
        return lineBottom - layout.getBottomPadding();
    }

    return lineBottom;
}