/// <summary>
/// Move the selection end to the buffer offset physically below
/// the current selection end.
/// </summary>
/// <remarks>
/// Move the selection end to the buffer offset physically below
/// the current selection end.
/// </remarks>
public static bool extendDown(android.text.Spannable text, android.text.Layout layout
)
{
int end = getSelectionEnd(text);
int line = layout.getLineForOffset(end);
if (line < layout.getLineCount() - 1)
{
int move;
if (layout.getParagraphDirection(line) == layout.getParagraphDirection(line + 1))
{
float h = layout.getPrimaryHorizontal(end);
move = layout.getOffsetForHorizontal(line + 1, h);
}
else
{
move = layout.getLineStart(line + 1);
}
extendSelection(text, move);
return(true);
}
else
{
if (end != text.Length)
{
extendSelection(text, text.Length);
return(true);
}
}
return(true);
}
private static int chooseHorizontal(android.text.Layout layout, int direction, int
off1, int off2)
{
int line1 = layout.getLineForOffset(off1);
int line2 = layout.getLineForOffset(off2);
if (line1 == line2)
{
// same line, so it goes by pure physical direction
float h1 = layout.getPrimaryHorizontal(off1);
float h2 = layout.getPrimaryHorizontal(off2);
if (direction < 0)
{
// to left
if (h1 < h2)
{
return(off1);
}
else
{
return(off2);
}
}
else
{
// to right
if (h1 > h2)
{
return(off1);
}
else
{
return(off2);
}
}
}
else
{
// different line, so which line is "left" and which is "right"
// depends upon the directionality of the text
// This only checks at one end, but it's not clear what the
// right thing to do is if the ends don't agree. Even if it
// is wrong it should still not be too bad.
int line = layout.getLineForOffset(off1);
int textdir = layout.getParagraphDirection(line);
if (textdir == direction)
{
return(System.Math.Max(off1, off2));
}
else
{
return(System.Math.Min(off1, off2));
}
}
}
/// <summary>
/// Scrolls the specified widget to the specified coordinates, except
/// constrains the X scrolling position to the horizontal regions of
/// the text that will be visible after scrolling to the specified
/// Y position.
/// </summary>
/// <remarks>
/// Scrolls the specified widget to the specified coordinates, except
/// constrains the X scrolling position to the horizontal regions of
/// the text that will be visible after scrolling to the specified
/// Y position.
/// </remarks>
public static void scrollTo(android.widget.TextView widget, android.text.Layout layout
, int x, int y)
{
int verticalPadding = widget.getTotalPaddingTop() + widget.getTotalPaddingBottom(
);
int top = layout.getLineForVertical(y);
int bottom = layout.getLineForVertical(y + widget.getHeight() - verticalPadding);
int left = int.MaxValue;
int right = 0;
android.text.Layout.Alignment?a = layout.getParagraphAlignment(top);
bool ltr = layout.getParagraphDirection(top) > 0;
{
for (int i = top; i <= bottom; i++)
{
left = (int)System.Math.Min(left, layout.getLineLeft(i));
right = (int)System.Math.Max(right, layout.getLineRight(i));
}
}
int hoizontalPadding = widget.getTotalPaddingLeft() + widget.getTotalPaddingRight
();
int availableWidth = widget.getWidth() - hoizontalPadding;
int actualWidth = right - left;
if (actualWidth < availableWidth)
{
if (a == android.text.Layout.Alignment.ALIGN_CENTER)
{
x = left - ((availableWidth - actualWidth) / 2);
}
else
{
if ((ltr && (a == android.text.Layout.Alignment.ALIGN_OPPOSITE)) || (a == android.text.Layout.Alignment
.ALIGN_RIGHT))
{
// align_opposite does NOT mean align_right, we need the paragraph
// direction to resolve it to left or right
x = left - (availableWidth - actualWidth);
}
else
{
x = left;
}
}
}
else
{
x = System.Math.Min(x, right - availableWidth);
x = System.Math.Max(x, left);
}
widget.scrollTo(x, y);
}
/// <summary>
/// Move the cursor to the buffer offset physically below the current
/// offset, or return false if the cursor is already on the bottom line.
/// </summary>
/// <remarks>
/// Move the cursor to the buffer offset physically below the current
/// offset, or return false if the cursor is already on the bottom line.
/// </remarks>
public static bool moveDown(android.text.Spannable text, android.text.Layout layout
)
{
int start = getSelectionStart(text);
int end = getSelectionEnd(text);
if (start != end)
{
int min = System.Math.Min(start, end);
int max = System.Math.Max(start, end);
setSelection(text, max);
if (min == 0 && max == text.Length)
{
return(false);
}
return(true);
}
else
{
int line = layout.getLineForOffset(end);
if (line < layout.getLineCount() - 1)
{
int move;
if (layout.getParagraphDirection(line) == layout.getParagraphDirection(line + 1))
{
float h = layout.getPrimaryHorizontal(end);
move = layout.getOffsetForHorizontal(line + 1, h);
}
else
{
move = layout.getLineStart(line + 1);
}
setSelection(text, move);
return(true);
}
}
return(false);
}
private static int findEdge(android.text.Spannable text, android.text.Layout layout
, int dir)
{
int pt = getSelectionEnd(text);
int line = layout.getLineForOffset(pt);
int pdir = layout.getParagraphDirection(line);
if (dir * pdir < 0)
{
return(layout.getLineStart(line));
}
else
{
int end = layout.getLineEnd(line);
if (line == layout.getLineCount() - 1)
{
return(end);
}
else
{
return(end - 1);
}
}
}